[arm-allstar] I think I found a new BF-888s board, need help finding COS

[Joe Puma]

Here is the underside of the radio; that heat sink on the final was added by me as I ditched the shell, it literally wasn’t doing anything to section off the RF areas of the radio nor offer any cooling.

Double check which pin is needed for COS. in my picture i'm wired to pin 1. I believe I had to change it to pin 2 as there wasn’t correct signaling on pin 1. Please double check. 

btw, I powered the radio and Rpi with same 12v-5v power regulator. I added 2 diodes in series to bring the 5v down a little for the radio but the 888 will work off of 5V you just need to make a setting in the radio to allow the radio to power when over-voltage ( I use CHIRP), otherwise it won’t turn on. 


73
Joe
KD2NFC





> On Aug 11, 2018, at 12:57 PM, Doug Crompton via arm-allstar <arm-allstar at hamvoip.org> wrote:
> 
> Andy,
> 
>   There have been many iterations of the 888 but in all cases they retain the 8 pin chip where COS is picked up. I am attaching a photo from the howtos at hamvoip.org <http://hamvoip.org/> showing the chip. There are two 8 pin chips and part numbers are often hard to find. One of them is the spot - pin 1. Placement of the chips changes so you will need to check which one it is. The COS goes high on signal - 0V no signal, >2.5V signal.  If you cannot find a connection on the circuit side you will have to remove the board to get to the chip. Info on doing that is in the howto.
> 
> 73 Doug
> WA3DSP
> http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>
> 
> 
> On Sat, Aug 11, 2018 at 12:38 PM, "Andrew Hull KE8HEV via arm-allstar" <arm-allstar at hamvoip.org <mailto:arm-allstar at hamvoip.org>> wrote:
> Hello All,
> I'm in the process of building a simplex node (RA-40 & BF-888s).
> 
> The BF-888s that I received has a date stamp on the board of 2017-11-04. I
> believe that this is an updated revision from the board that Chris Hood
> documents here:
> http://www.chrishoodblog.com/allstar-node-with-bf-888s-short-board/ <http://www.chrishoodblog.com/allstar-node-with-bf-888s-short-board/>
> 
> The design looks similar enough that the RX Audio, PTT, and Mic Audio
> appear to be in the same places. However, I'm at a loss for COS.
> 
> Has anyone already solved the mystery for this revision? My Google attempts
> have turned up nothing.
> 
> If not, could anyone offer some advice on how to find it myself? I consider
> myself in the "knows enough to be dangerous" category of low level
> electronics. So, with a friendly shove in the right direction, I hope I can
> find it.
> 
> Here's a photo of my board. I haven't taken it off the heatsink to get a
> look at the other side.
> https://photos.app.goo.gl/pcnRfK2X7Pt8HhXKA <https://photos.app.goo.gl/pcnRfK2X7Pt8HhXKA>
> 
> Thank you!!
> 
> 73,
> Andy
> 
> --
> Andy Hull
> KE8HEV
> 
> [Any errors in spelling, fact, or tact are transmission errors]
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