Programming a smart effector



  • I got some custom white PCB smart effectors made. I'm going to populate them sometime soon, and I would like to know how you guys program them. I planning on using one of my Teensys as an ISP for avrdude and connecting it up with a little pogo-pin connector I'm printing. I was looking at the firmware repo though, and I saw for the compilation output only a .elf was available. Don't I need a .hex?

    Besides that, any other holes in my plan?


  • administrators

    That sounds viable. Most attiny programmers accept both .elf and .hex files. I don't know about avrdude, I haven't used it for years. I program the prototypes of our attiny based units using an AVRISP Mk 2 and Atmel Studio.



  • @dc42 great! Do you know if a micro loaded up with the ISP arduino sketch will work with Atmel Studio, or is this more something that I'd be alone on?


  • administrators

    @curieos said in Programming a smart effector:

    @dc42 great! Do you know if a micro loaded up with the ISP arduino sketch will work with Atmel Studio, or is this more something that I'd be alone on?

    I don't think Atmel Studio can drive an Arduino running ArduinoISP. But you can convert a .elf file to a .hex file. See https://stackoverflow.com/questions/19458031/how-to-create-a-executable-hex-from-elf-file-format for one possible way. I haven't tested this, but I think Arduino IDE uses a similar command.



  • @dc42 do I need to burn a bootloader? I think I have everything wired up correctly, but I seem to be having some issues.



  • I think I got the wrong model of ATiny44s, mine are too small to solder on the board reliably. What model of ATiny are you guys using?



  • @curieos said in Programming a smart effector:

    @dc42 do I need to burn a bootloader?

    No.


  • administrators

    @curieos said in Programming a smart effector:

    I think I got the wrong model of ATiny44s, mine are too small to solder on the board reliably. What model of ATiny are you guys using?

    We use the smallest Attiny44a, that comes in a square leadless package. You have to reflow solder them. I soldered the prototypes myself, using a Mylar stencil to place the solder paste accurately, and a hotplate.



  • Is that a 3x3mm chip? That’s what I have I think, and the pads on the chip barely touch the pads on the board



  • schematic says attiny44a-mmh which is the 3x3 mm vqfn version, pads are supposed to be under the chip


  • administrators

    That's right, the pads are under the chip.



  • Okay, guess I’ll have to give it another shot. Thanks for the help!



  • You can pull it of in a frying pan, but there really isn't any substitute for solder paste or pre-tinning the pads and applying good flux. Google and youtube will show lots of home gamer ways to do smd assembly with basic tools.



  • I have access to a reflow oven, hot air station, and several soldering irons. Also solder paste and flux. Might have gotten too much solder on the center pad, we will see when i try again.



  • No matter how hard I try it wont line up, I don't think these fit on my board. I suspect that when I opened up the board files in KiCAD, since my libraries are different, it chose a slightly different footprint, maybe for the 4mm version. I'm ordering some new ones that should hopefully work just fine.



  • It was the wrong part number, I got the new one installed and avrdude accepted it for programming.



  • To continue this, several months later. I finally got around to building a second one. Unfortunately neither of them seem to work. I am able to program them, avrdude recognizes them as attiny44s, but the status light never comes on, and the probe seems to trigger somewhat randomly. Any ideas on troubleshooting? Everything else works fine, all the other lights light up, the only issue is probing. Both boards seem to have this issue.


  • administrators

    @curieos said in Programming a smart effector:

    To continue this, several months later. I finally got around to building a second one. Unfortunately neither of them seem to work. I am able to program them, avrdude recognizes them as attiny44s, but the status light never comes on, and the probe seems to trigger somewhat randomly. Any ideas on troubleshooting? Everything else works fine, all the other lights light up, the only issue is probing. Both boards seem to have this issue.

    If the green trigger LED never comes on, I suggest you sort that out first. Check that it is fitted the right way round and the value of the series resistor is correct. Also, make sure you are using the correct firmware version - there are different firmwares for the version 1 and version 2 effectors.


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