 And welcome to Slydita. Hey everybody and welcome to my desk. I hope everyone is staying nice and cool. It's been hot here in New York, but that means it's time to stay in and have some ice tea and work on electronics, which is what I've been doing. Mr. Lady, do we have any updates, news, things we want to tell people? We'll be doing show and tell this week lots of new products and videos and more surprises. We're pumping out a lot of new products and open source code that'll empower a lot of people to do a lot of new things. Slydita will show you exactly what I'm talking about. There's a lot of folks who like to make things with displays or with Raspberry Pis or with microcontrollers. And we're getting back to some of the really tough projects. I'm going to literally dust off a project. Yeah, literally it's like covered in dust. Yeah. That's how long it's been on my desk. And let's see what's on your desk. All right. Let's go to my desk and we'll check it out. Okay. So here is what I've been working on this week. And this is, again, like a 2020 era project that got just delayed because TFT prices just skyrocketed. I don't know when people remembered, but these displays went from being $5 to $10 to like $30 a piece. And I was like, okay, I can't do any projects with TFTs and chips were unavailable. Diodes weren't available, but everything's really calmed down a lot. And so I'm going to get back to some of the stuff that I designed, but didn't get to finish. So this is your standard box standard 50, sorry, five inch diagonal 40 pin TFT display with TTL. I got called TTL RGB display. So this has eight bits red, eight bits green, eight bits blue parallel, v-sync, h-sync data enable, pixel clock, on off, backlight with a bunch of LEDs and series. And this one doesn't have a resistive touch screen. And sometimes these screens, this is a 4.3 inch one. I think this is 800x480 actually, but it's 4.3 inch. It's a little less diagonal. And you'll see it's got the same connector. It's a very, very standard connector. I call this 40 pin TTL. And it's also got a separate capacitive touch overlay. So this is a separate, totally separate electronic piece. It's glued on top. So you can see there's the TFT just like this. But it's also got this glass capacitive touch screen. And then these are often like focal tech, FT something, something, something. They're almost all compatible with each other. I squared C, capacitive touch chips. And so this is a six pin connector, power, ground, reset, SCL, SDA and IRQ, pretty much. So maybe address instead of reset. But even it says actually, if we can, let me focus in on it. It's kind of nice. You can even see here it says SCL, SDA, VDD, reset, and ground. One thing I will notice is that even though this 40 pin connector is like nearly standardized, the six pin connector for the capacitive touch is like all over the place. Like there are sometimes the connectors over here, sometimes, you know, the connector goes long, sometimes it's flipped, sometimes it's this way. Sometimes it's one pin out, one times the other, sometimes it's six pin, sometimes it's eight pin. And that part's not as a standard. Although six pin is very, very common. So, you know, in the shop, go to the computer, please. I'll show these in the store. So, you know, you have in the store, we have the resistive touch and the non-resistive. I'm going to get capacitive touch now that I'm kind of doing more of the stuff. And I'm like, oh, I should have a capacitive touch version of these displays. And traditionally how you would connect this to something like a Raspberry Pi is there's two kind of known ways. One, you go with HDMI. And an HDMI backpack like this one uses a TFP401. There's actually a couple chips that do this. There's like an AD78 something something or 7644. There's the RT622 series, which has a scalar in it, which is kind of nice, but is otherwise very hard to use. Documentation sucks. It's like you've used an AD581 compiler. But one of the annoying things about these, well, these displays work great. What's nice is it's HDMI. HDMI universal, which means you can plug this into your Xbox. You can plug it into your GoPro camera. You can plug it into your phone. You can plug it into your Raspberry Pi. You can put it into your Windows box, your Mac. It always works. But these chips are very hot. They take up a lot of energy. They draw like, I think, 200, 300 milliamps at five volts. And they're not cheap. These chips are also like $8 apiece. They're kind of expensive. Now, they don't know which is why this is like, it's like, whoa, it's so many bucks. Why? Because this chip is like $8 to $10. And then, you know, you add the cost of assembly and the TFT. So even though these work great when you have HDMI, they're expensive. And then the other way you can connect displays is with a the DPI, the display parallel interface on a Raspberry Pi. And this is like the, what I call like a DPI TFT KIPA. It's not quite a hat. It's a little bit less because it uses all the pins. And what this does is it has every GPIO almost from the Raspberry Pi connected to usually not all 24 bits. Usually we do 18 bits. So like 666, red, green, blue, which is still very high quality color. Like most people can't tell the difference between, especially for these small screens, the difference between 18 bit and 24 bit color is huge. And then, of course, the V-sync, H-sync, pixel clock. And you see, you can even tell like definitely when the Raspberry Pi folks designed the Raspberry Pi 2 by 20 connector, you can see that they definitely made sure that they had all the pins available to be able to use this interface because the pins are very fixed. Like you can't change which pin is V-sync or H-sync or red, green, blue. They're like, they're very fixed in the documentation. I think Raspberry Pi DPI pin out. I think they have a, yeah, they have the documentation here. Yeah, DPI. There's a couple different configurations, but for the most part, you know, you can't really change the pins. And not only can you not change the pins, but, well, this one doesn't have it, but like the H-sync and the V-sync are on like the I-squared C-pins. So if you want to do something like add capacitive touch or you want to add resistive touch through I-squared C, you have to do like bit-bang I-squared C and then device overlays and change the pins. And it's like, basically, it's annoying, especially then you're like, oh, I want to connect an I2S amplifier for high quality audio along with my nice screen, you can't because the I2S pins are completely overtaken by the DPI pin out. So the other option is you use the DSI connector. So let's go back to the overhead. I'll show off the DSI connector. So the DSI connector is this thing, which says display. Remember, this is camera and display. The only thing is the Pi zeros don't have this connector. So it's, you know, the one thing basically that got left off. But the, all the Raspberry Pi A pluses and the B pluses have them. They've had them for quite a while. And the CM modules, the compute modules also have access to the DSI, the pin out. And what's neat about this is it's a two-lane MIPI interface that's differential, two lanes. So data one, data two differential and clock differential. So six data lines. And it can control like fairly large displays. Like two lanes will get you I think up to like definitely 720p. But I think you can even get like, you know, like 1000 by 720 pixels or something. You can get fairly large displays, maybe not 4k. I think for that you need four lanes. I don't know the exact math, but you can get, you know, nice little displays. And in fact, that's how the Raspberry Pi, if you go to the computer again, I'll have a lot of back and forth today. So the Raspberry Pi display. So the foundation display, you'll notice if you look at the screen here, oh, that looks just like, you know, it's kind of your standard ish 40 pin. You've got lots of parallel lines here. So it's RGB. And then it connects to this driver board. And the, I think on the back, and then the driver board has the DSI and it also has, it looks like USB power. And then there's like a microcontroller. And then this is I think panel power. I actually don't know what the USB is for. I know you can power it from you can give it extra power, but yeah, it sits underneath. And you can give it extra power. And then this is the DSI cable. You'll notice that other than the power pins, the GPI is free. And so is the HDMI. Okay, so, and then you have a nice case. So it's a very sweet. This one has capacitive touch. It's quite fancy. So this is, and the chip that it's using on here is I believe the Toshiba TCX something, something, something, which is the Toshiba DSI2 RGB. It is the TX. It's probably something like the TX58778XBG. Wonderful chip. I'm sure it's great. It's not inexpensive. It's a BGA. If you know me, I'm not a huge fan of BGAs because they're like really annoying to rework and pick in place. You know, you can't lay them out easily. Usually you need like a four layer board. So while this chip is I'm sure super awesome, what I wanted to do was instead use the ICN6211 and the ICN6211, which doesn't have great documentation, but we can maybe Google something. And it's by, whoops, sorry, I went to my other tab. Yeah. So this is a also DSI2 RGB. It is a lot less documented than Toshiba, but it does do kind of what you want. They can give you up to four lanes of RGB and then, sorry, of DSI data. And then they can convert it to 24 bit color with HNV sync DEP clock. And it also does I-squared C for control. And then you just have to give it the data and a clock signal and some power. And it's pretty much good to go. The only thing that's a little annoying is that there's there's no good data sheet. There's all these registers, but the registers are not you can see there's one register documented. Otherwise it's like, hey, here's some weird stuff, but for some reason they always tell you how an I-squared C works. And you're like, I know how I-squared C works. I want the register map, but they don't give that to you. Instead, there's this tool I think that they distribute. And then you tell it kind of what you want for, you have to tell it how big the display is and the front porch, the back porch, the HNV sync width. This is all in the TFT data sheet. So if you go to the data sheet for these, they'll give you not only the pinouts, but at the middle or bottom, they will tell you your timing. Hold on, let me find the timing. Here it is. So each display has their own like, you know, they're kind of loose with it, but you want to get it somewhat close. Basically, the frequency that they want to drive the pixel clock and the porch size is in the pulse polarities. Like some have like a negative h-sync and some have a positive h-sync. So you just have to like kind of look at this up and then you enter it in. This is, you know, what the timing looks like for the different pulses that let the chip in the TFT display synchronize. Yeah, here you go. This is the different porch widths, these little signals. So, okay. So the ICN 6211 is a, hold on, so is that chip in its alternative? And the nice thing about it is it's inexpensive. It's like a dollar or less, which is like pretty sweet because again, that HDMI chip, the TFP 401 is like $6 to $8. So $1 is a really good price. So a longish time ago, I designed a board that would let me control, connect to TTL displays from DSI. So, sorry, let's go back to the overhead. So now I've introduced it, I can actually show it off. So this board has the ICN 6211 and it's got the DSI connector going here and, you know, it just connects from the Raspberry Pi. This is power, and I'm actually also using this to track how much power draw this is taking, and it's like very little, almost all the power is going to the data, to the backlight. I think this only draws maybe 50 milliamps, if that. It's definitely cool to the touch, which is good. On this version, I actually put an AT, at SAMD 21, because one of the weird things about the ICN 6211 is it responds to every I squared C address, like whoever wrote the I squared C peripheral, like kind of slapdashed it. So it can't share any I squared C, like you don't want it on your main I squared C bus, because it'll bash everything else on there, including like your capacitive touch or resistive touch driver chip. So I thought, oh, I'll have like the SAMD set up, because you don't have to set it up on boot. You set up the I squared C commands to configure the display, and then like it would go to sleep. But then I kind of messed around some more, and decided to do a slightly different design, which I'll show. You got a backlight driver here. This will give you, you know, you can configure it by default. It's 25 milliamps, constant current, but you can go up to 100 milliamps, constant current, various I squared C. So there's a lot of I squared C. There's actually I squared C that comes, that comes through the DSI. And so actually what I did on this one is I bridged the DSI to the ICN I squared C because I don't have capacitive touch going yet. So I'm like, well, I'll just take up every I squared C address on the DSI port, get it configured, and then we're good. And actually you'll notice like, Hey, why is this screen all like funky now? That's because actually the screensaver kicked in on the Raspberry Pi. And when it does it, it's the DSI chip doesn't, it definitely doesn't get signal anymore, but there's no communication between the DSI to RGB chip and the backlight driver. So it doesn't the backlight driver doesn't actually know that it should shut off the backlight because it's completely separate from the RGB logic. So there's something that again, you would probably use them. I'm going to use a microcontroller and I've done this before. I'll have it listen to the V sync pulse, because it's supposed to come every 60 Hertz. And if you don't get a V sync pulse in like, you know, half a second, it'll shut down the PWM to the backlight drivers. That's a really easy way to just be like, it's a little watched, use the V sync as a watchdog timer. So yeah, so this is, if I hit return on this keyboard, it's like pop comes back up. So yeah, it's just, you know, it basically doesn't know to turn off the backlight. It's that's the trade off for this chip. It's not super smart. Whereas I like the RTD 2600 series is definitely like, it's a, you're programming the chip inside and you can have it do all sorts of logical things and be smart and all that. So for interfacing to this chip, you do have to, you know, you have to, once you've sent it to the I2C commands, it then just takes DSI to TTL. It does that for you, but you have to set that up. So if you go to the computer, there is a library and we've hired Timon to do this work because there's like this data sheet, there's this weird ass tool, but we're like, ah, can you like make it into like a library and also of course test the hardware and Timon has done some stuff with these chipsets. So he's like, oh yeah, like I know exactly what you want. So he's a great job and he made a library and some example code. And then we, we just run, this is the Raspberry Pi. I run the test on the code to configure it on the Raspberry Pi for now. And then eventually this register right will be done by a separate microcontroller. So this is just the test where we, you configure all the sizes of the back ports. This is being configured to 800 by 480. And you set up the PLL and you know, you reset it and you're like, go, go chip. So we, I did, we do this board a little bit. This version actually has a separate microcontroller that's going to be driving the I squared C. This one's also set up to drive these square displays. So if you go to the overhead, I'll show this real fast. We'll wrap up here in a moment. So this is like a 480 by 480. And this is 720 by 720. And these are like funky square displays. One has capacitive touch and this one doesn't. And they also have a 40 pin, but the 40 pin is like different than the standard 40 pin, which I understand why, but it's a little annoying. One, the capacitive touch pins actually go into the 40 pin. It's convenient. You don't have that separate, you know, like, hi, I'm like, dangly. You don't have the dangly. The dangly has been integrated into this connector. And there's also a SPI interface and two extra GPIO pins. And the SPI interface is used to configure the onboard TFT driver chip. So not only do you need I squared C to connect and set up this DSI to TTL, this TFT is like wonderfully simple. You send it signal and just starts displaying. With these displays, the square ones, you have to set up a configuration through SPI to tell it, no, no, you're a 480 by 480. And this is your RGB order, just like you would do with an SPI only display. But basically after you set up that initialization, you then pipe in TTL. So like, there's a lot of things to balance. So the last thing before we go on to the great search is I'm going to literally dust off this. So one of the things I worked on many, many, many years ago is I had one of these cool displays. This is unfortunately quite delicate. So this is a four inch 800 by 480. So it's really nice. It's got the same resolution as this five inch display, but it's a nice compact four inch and I even have a version that has a capacitive touch overlay on it. Really good looking. These four, you know, cell phones, obviously it's even cell phone, you know, it looks like a cell phone. It's got the same size and shape. And what I did is this display, it has a 40, it also has that 40 pin connector and it has like that funky, you know, it's RGB, but also has the SPI communication. So I used, here you can see like a little trinket, a SAMD 21 that would connect to the SPI and configure it and set it up and then tell it, okay, you can then take RGB data and then over here I had a, you know, Raspberry Pi 40 pin breakout board that I wired all the red, green and blue and clock and data pins and I could get it set up here. And then I did design a board for it as well. So, you know, I'm showing this here so you can see it. Let me see if I can that's a little blown out. Sometimes if they do this, there you go. So, you know, it's a very nice crisp display and you can see the text and it's like IPS so it works from an angle. And this is basically the version of this breadboard, but on a full PCB. So on the back here, so you've got that 40 pin TFT and then there's an at SAMD 09 here. And this is what is communicating with this over SPI and also handles that backlight thing. So again, it listens on the v-sync. And if the v-sync doesn't go, doesn't drop every, whatever, a couple milliseconds, it turns off the backlight because it's like, okay, the signal's gone. And then this was actually DPI, right? Because this was before I had this ICN 6211. So, like every, you can see every single GPIO got used. Like it's a lot of routing. But, you know, at the time, I was like, well, this is kind of as good as going to get. And then like, you know, 2020 happened. And then 2021 happened. And then I kind of like, this was literally been sitting on my desk, dusty for the last couple years, but I've now revised it. So, our last thing as we go to the computer, if you can pop to the computer, yeah. So I revised it last night. And so this is the same board, but now instead of having that gigantic 2x20 connector where you use all the GPIO pins, it's all going to a ICN 6211. You can see here through these little resistors or resistor packs. The DSI connector, I put a stomach QT on here and you can switch which port you want to use iSquad C on. And then I've got a AT Tiny 1616 that's going to do the iSquad C and SPI on boot noodling. Like when you power it up, it'll quickly do all the resets, it'll write the data to the iSquad C and SPI ports, and then handle the backlight driving as well. So it'll actually listen over iSquad C and PWM the backlight. So you can actually do dimming and lighting. I don't know if it'll have a kernel driver, but at least it'll be over a very simple iSquad C interface to set up and write the PWM to change the backlight as desired. So you know what's happening. I'm getting back to this. This has literally been on my desk for, I mean, there's this funny on my desk, there's like a dust, there's like an outline where the dust isn't, because this is what's sitting on there in the back for the last like three, four years. But you know, I've got all these cool displays, I'm going to get this working. So I'm going to start just getting the breakout working, getting this, you know, this four inch hat back in business, and then I'm going to try doing like round displays, square displays, bar displays, all using the DSI interface. So that's a lot, but we're getting to it. And then, you know, the last piece is we have to get the device tree overlay going for these. But you know, we kind of took the one from the, this is my setup, I should have the detail open. But we have a, we have a device to overlays basically the Raspberry Pi seven inch slash the ICN 6211 and we kind of mush them together and pull some stuff out and we think we can get something going. This will be great because there's a lot of weird ass displays that you want to use, but you don't want to use every GPIO pin on your Raspberry Pi to drive it. I think this could be super fun. Also for you're making adorable little CM4 products with the compute module. All right, so let's go to the great search. The Great Search brought to you by DigiKey. And if you read every single week, Lady and User Power of Engineering help you. Yes, you find the things you need, Lady. And what is the great search of the week this week? And this actually by a request somebody mailed in. And let's go to the overhead and I'll show what they were asking. So working on this project with the DSI displayed on the Raspberry Pi computer, and actually now a lot of single board computers because they've all cloned the Raspberry Pi, there are these connectors, the DSI, the display connector, and then the CSI camera interface. And one thing that definitely happens, even to me, I'm very careful, is the clip comes out of the connector. And then if the clip comes out the retaining clip, you can't use it. And it's very often the little there's a little ear and the ear snaps and it like flies off the room and the cat grabs it or whatever or gets swept up. You don't want to throw away your beautiful Raspberry Pi just because it's got this clip. So let's find replacement connectors. And then we can always reuse the clips. You can gently remove them and replace them for the camera or display interface. They're both the same connector. So let's go to DigiKey. Oh, and I was showing earlier like there's cool weird square displays. Check out previous video if you have it. Okay, so what we want is the same connector for the CSI or DSI. And those happen to be, and I know they are 15 pin FPC, the flex print circuit board connector, flexible connector. We don't want the assembly. We just want the connector itself. Yeah, that's right. It looks like this. I like that they added images, options. Actually, let's just go to the whole category and then okay, so contacts, I think we want the one that has like 19,000 available. Let's see. Yeah, so this is now talking. Yeah, there's different configurations and pitches and pinouts. Okay, so the first step I always because we want to actually be able to buy this we're always going to go with the active and number positions. How many pins? 15. We don't want like half loaded. We want like full 15, so just pick 15. And then pitch. For this, you know, you have to note the pitches. You can use your handy calipers to measure the distance between the pins. There are standard sizes, but like 99% of the time, it's going to be either 0.5 millimeter or one millimeter. Once in a while, there's others, but it's super duper rare. If it's like very close together, it's almost certainly 0.5. And if it's a little farther apart, it's one. And if it's alternating, it's like sometimes 0.3. But it's this one in particular is going to be one. Oh, and then once in a while, it's 0.1 inch, like really fat. There's old stuff. Next up, do we want surface mount or through hole? Well, on the Raspberry Pi, it's a surface mount connector. So you want surface mount and also grab the dash because it could be, there's some that aren't categorized. And let's also say only in stock because we want, we want to be able to purchase this today. So this is what we got so far. Whenever I have like, you know, a couple dozen, that's when I start looking and I'm like, okay, what would we have? Okay, these are starting to look good. One thing is, is that the, for the board of designing, I wanted a right angle so it sticks out to the side. But for the Raspberry Pi, if you want to replace the connector, it's a sticking up style, which is, and you can always see what you, you're like, oh, this is the style I want. And then look to see the mounting type. So that's surface mount, non-right angle. So let's go to surface mount, not right angle. Okay, so only 10 options. So now we're, now we're really talking. Okay, so then you can see that, you know, there's a lot, still a lot of options. One thing is that some of these connectors, you see, they don't have a retaining clip. You can see the retaining clip here and here. It's a little piece that you pull out and then it kind of jams the cable in place. Make sure it doesn't pull out too easily, which, you know, depending on some designs, you want the cable to be able to pull out very easily so the cable doesn't get damaged and it's easy to insert. But in this particular case, we want it to have the retaining clip. So if we look, this is called a slide lock. So these two here are slide lock. This, see, it looks like it has a slide lock, but I guess it doesn't. So we're going to go with slide lock. Okay. And now we're down to our three options. So there's the three options. And then what I do is actually just look at the connector. So let's go to the overhead real fast and we'll look at what the connector looks like. So, you know, it looks like it's kind of flat because, you know, we want to match the connector as much as possible. And it's got little ears that stick out the side over here. Okay, so let's go back to the computer. So looking at these, you know, this one actually looks the closest. The coloring is also the same, too, which by the way, sometimes, you know, you might not get the right color. The color doesn't matter. It's just like it to help you indicate which one you think it is. But it's got the little ear sticking out and it's definitely got, it doesn't have any like extra notches or anything. So I think that this is going to be the closest. And it's only 50 cents. So if you want to fix your Raspberry Pi, you know, I wouldn't necessarily place a whole order just for this connector. But let's say you have a bunch of them that you want to fix. You get 10 pack or if you're ordering stuff from Digi-Key anyways, toss this in and then you'll have it for when your Raspberry Pi connector, if you pull it and you break it, you'll have these ready to go to repair it at that time. I always, I have a couple of these always and I have to fix the one on my desk because I broke the clip. But this is my recommendation. So try it out, FFC 382015G from GCT. Good option, 50 cents. And that's research. All right, that's a show for tonight. Thank you so much everybody. We got a big week ahead. Thanks for joining us. We can't like have big, gigantic eyes. Yeah, we can do it. Absolutely. Yeah. All right. See y'all.