Title: Another BP build
Post by: Sleepwalker3 on July 24, 2013, 01:30:00 pm
Post by: Sleepwalker3 on July 24, 2013, 01:30:00 pm
Hi Guys,
Probably in the wrong section to post this, but here is a couple of pics of the BPV3.5a SOIC built from a DP giveaway (thanks DP :)
All pretty much standard, though as yet the LEDs haven't been fitted to the rear - I didn't realise at first that they had LEDs on the rear as well. All went together pretty quickly. Putting it together using the circuit diagram, I initially fitted a MIC5205-3.3 to VR1 before remembering the article about oscillations with very low ESR caps. Sure enough, I got the low level oscillations at something around the 150-200mV mark. I later swapped to a NCP700BSN33T1G and that sawtooth oscillation disappeared, as others had found.
Thus far it's just been plugged in and the power LED come on and the PC recognised the FTDI. Next step is to program the Bootloader in (when I work out which one I need!) using a Pickit3 and then the firmware (whichever version that is - too many SVN entries/models/versions gets me bamboozled!)
Probably in the wrong section to post this, but here is a couple of pics of the BPV3.5a SOIC built from a DP giveaway (thanks DP :)
All pretty much standard, though as yet the LEDs haven't been fitted to the rear - I didn't realise at first that they had LEDs on the rear as well. All went together pretty quickly. Putting it together using the circuit diagram, I initially fitted a MIC5205-3.3 to VR1 before remembering the article about oscillations with very low ESR caps. Sure enough, I got the low level oscillations at something around the 150-200mV mark. I later swapped to a NCP700BSN33T1G and that sawtooth oscillation disappeared, as others had found.
Thus far it's just been plugged in and the power LED come on and the PC recognised the FTDI. Next step is to program the Bootloader in (when I work out which one I need!) using a Pickit3 and then the firmware (whichever version that is - too many SVN entries/models/versions gets me bamboozled!)
Title: Re: Another BP build
Post by: Menno on July 26, 2013, 12:28:22 am
Post by: Menno on July 26, 2013, 12:28:22 am
The LED's are either on the front or the back.
Furthermore, pins 12 and 13 of IC3 (4066) should be connected.
Furthermore, pins 12 and 13 of IC3 (4066) should be connected.
Title: Re: Another BP build
Post by: Sleepwalker3 on July 27, 2013, 01:08:15 pm
Post by: Sleepwalker3 on July 27, 2013, 01:08:15 pm
Thanks Menno, that makes more sense. I didn't end up fitting the rear ones, as I know the brightness can drop significantly between LEDs depending on the LED thresholds and in any case the cables come out the front, so the rear LEDs wouldn't generally be useful to me anyway.
Thanks for the tip about the 4066, I did see on the circuit that pin 13 wasn't connected and thought it looked odd, but didn't follow it up. You probably saved me a lot of frustration :)
Now all I have to do is sort out what bootloader and firmware, then setup the PicKit3 and presumably MPLABX, or is MPLAB 8x the one to go for still (Win)?
Thanks for the tip about the 4066, I did see on the circuit that pin 13 wasn't connected and thought it looked odd, but didn't follow it up. You probably saved me a lot of frustration :)
Now all I have to do is sort out what bootloader and firmware, then setup the PicKit3 and presumably MPLABX, or is MPLAB 8x the one to go for still (Win)?
Title: Re: Another BP build
Post by: Sleepwalker3 on July 27, 2013, 01:19:35 pm
Post by: Sleepwalker3 on July 27, 2013, 01:19:35 pm
Would be a good idea for somebody to change the circuit here http://http://dangerousprototypes.com/docs/images/4/4d/Cct-BusPirate-v3.5.png to make a note that Pin12 and Pin13 need to be connected. I would do it and submit, but I don't use Eagle (tried that a couple of times, but my forehead got sore from whacking it against the screen!)