How to flash the firmware

[bastard]

I'm writing this because I was screwed about flashing my TV-B-Gone. What happened? I connected my programmer and did a make and a make program. I spare you the details and several error messages - it did not work. However something happened - my TV-B-Gone got very hot! So I pulled out the batteries and grieved about my died attiny.

I did not look into this forum before flashing because what could get wrong by connecting a programmer to the isp header and start flashing ...

As others had this experience too - and this special behaviour is still not mentioned in the documentation - I want to mention it here: It is not possible to flash a fully assembled TV-B-Gone. At 29 Apr 2009 "lz3060" had explained this already:

You cannot use the on-board ICSP header to talk to the microcontroller once you have mounted the IR transmitter parts -- the loads on MISO and MOSI drive the voltage and cannot be used for communication. If you want to re-program the chip you either shouldn't mount the IR transmitter section (R1-R4 and/or the transistors and/or the IR leds) or come up with a breadboard setup with power and clock to place the chip on and speak to it.

And I totally agree with his/her proposal:

This should go into the tutorial or FAQ, or at least a topic with a good explanation of the problem should be made a sticky here. I should have found these topics before posting mine, true, but you should have mentioned the problem somewhere. Why provide an "optional" ICSP header that takes like 30% of the board area if it isn't usable?! Why not mention that "minor" detail somewhere?!

Now to my "solution". I ordered a Tiny25 Header, put the died attiny into its socket and connected the programmer to it. And surprise, surprise it wasn't dead. The flashing ended well and after putting the attiny back to its socket on the TV-B-Gone it worked again.

@ adafruit - would you please make this part of the documentation. And if possible, make this post sticky - or take it out and put it into a faq. Thank you very much.

Stefan

[ebeneblau]

I bought the TV-B-Gone at Chaos Communication Congress a few years ago, where the microcontroller was allready programmed.

Yesterday I built the new version without a kit and soldered it together. I tried to programm it, didn't work. And now I read this and I am angry.

Why is this Information hidden?

Thanks to the OP. Now I know at least, that I'm not stupid.

[franklin97355]

Not sure why it is not mentioned more prominently but I'm glad you got it figured out. Perhaps in the next revision of the docs ?

[adafruit]

its in the faq, last question. there is no 'easy' way to program the kit without removing at least one part

[franklin97355]

I just went to the FAQ, the last question was

I want more range! How can I make the kit more powerful?

Sorry but I found nothing there about flashing the chip. Perhaps it is in another FAQ?

[adafruit]

you have an older version cached

[Agent24]

Luckily I knew this before I started on my TV-B-Gone, and I programmed before I attached the LED circuitry...

I learnt a while ago it is best to try to actively seek out known design quirks\bugs\issues etc before you do anything, than wonder why it doesn't work afterwards...

[vxbinaca]

So let me see if I get this right, because I have an extra board I want to turn into a target board:

- No LED's, resistors, transistors or battery socket.
- Keep the crystal, the ISCP and IC socket, the two capacitors and switch?

Am I getting that right?

[adafruit]

sounds good!

[vxbinaca]

Fresh out of electrolytics and switches so all thats on the PCB now, along with a shielded and key'd ISCP interface. Too bad they don't make ZIF sockets this small I'll have to wait for Mouser to ship the parts I need in a few weeks.

Thanks adafruit for the wonderful kits and advice!

[Agent24]

I used a programmer which takes power from the target board (5 volts) of course with the AA cells such a programmer does not work.

Luckily the AVR in the TV-B-Gone operates up to 5.5volts, I powered both from the USB port and the programming worked fine.

Just something to consider...

[vxbinaca]

I'll make one with perf board eventually but for now I can use a spare PCB, and if I want finish it out later and make another TVBG.

[jedidove]

Having read the FAQ for the newest version, I'm left scratching my head as to why there isn't a small switch in series with R1 that way you could turn it toggle a "programming mode". Like mentioned above, it seems pointless to waste all that space in the PCB layout for a ICSP header if it's not going to be easy to program. It just gives a false illusion. Cutting the LED isn't "easy" because then it has to be replaced or half-assed fused with solder after programming and after a few times it's going to be very shoddy or a total nightmare.

I installed the header anyway since I'm a devout utilitarian and you never know when I might be out and want to reprogram it for some other prank or something (yeah slim chance but whatever), plus the space was already wasted so might as well make some use of it instead of leaving the header to sit in a parts bag.

I definitely think some solution needs to be made for this, and I don't see what's wrong with just a simple switch. If one is never implemented then it's probably better just to remove the ICSP header from the design to save space and prevent accidents from occuring.

[Agent24]

I think they don't bother because most people only just learn to solder when making this kit, and most probably won't be reprogramming it anyway.

A 1-way DIL/DIP switch would probably be the best option. A jumper on some pins could be used but the jumper would get lost quickly I imagine.

If you want one with a switch, you could always design your own board. I made a pretty nice board design which I uploaded here. You could easily modify it to add a switch or jumper for programming.

(In fact maybe I should add a switch to it myself...)

[jedidove]

I agree, but then it doesn't make sense why its included in the first place. I'll definitely consider adding one myself in the future, though if I'm going to make my own board I'd go all out and add an extra button and add IR jamming code to the device which might require a different chip.