Re: CM15A and MisterHouse Module Starting Point

[nobody@xxxxxxxxxxxx (Dave Houston)]

Neil,

I threw a preliminary web page together at...

        http://www.mbx-usa.com/cm15x.htm

with pictures of the two boards and schematics. I'll add bills of materials
with Mouser & Digikey PNs later as well as some assembly tips and my
suggestions on a communications protocol for both the main MCU and the RS485
network.

I still have 3 bare boards of each type that I will give to _qualified_
people who want to create firmware with the understanding that it will be
open source. They will need minor modification as I originally used 2 pins
on the PIC12F683 for RS485 TX & RX. Later, it dawned on me that I only
needed one.

Later, I will either provide the Gerber files or (if the supplier will
agree) a PN for ordering them.

Neil Cherry <njc@xxxxxxxxxxxxx> wrote:

>> I have designed two daughterboards for the CM15A (one RS232, one USB) which
>> replace the MCU with a socketed 16F88 and an SMT 12F683. The socket allows
>> the 12F683 to be programmed in circuit. The 16F88 can use a bootloader which
>> allows updating its firmware. The 12F683 handles RF (TX & RX) and controls
>> an ST485 which can interface with other RS485 nodes. I had planned
>> additional RF receivers on the RS485 network to handle multiple frequencies
>> and multiple protocols but that's open ended.
>>
>> It's looking more and more unlikely that I'll have the energy to complete
>> firmware for them. I'm willing to make the designs open source if you're
>> interested in taking them forward.
>
>Definitely interested but it may be put on hold until the end of
>February. I've been asked to write a book for Wiley called 'Linux
>Smart Homes for Dummies'. I'm announcing it now because I've signed
>the contract. I'm not sure writting a book is a good idea but it looks
>pretty on a resume. And yes I'm very much afraid of the community's
>opinion of what I'll be writing. I'm afraid I didn't have much choice
>for the chapters as the original author had to back out and I was
>second choice. Oh, Well
>
>Back to the CM15A, this sounds very cool! It would fix X10's dain
>bread interface. The CM15A had a lot of promise and they seemed to
>have crippled it (from what Woody, other and myself could figure
>out).
>
>> The bare boards cost $2.50 each (plus postage) for QTY 1 and that's with
>> soldermask and silkscreen on both sides. They would cost about $0.10 each
>> (plus air mail from China) in any kind of quantity. I might be able to
>> arrange a P/N with the board supplier so that individuals could order them
>> at the $2.50 price.
>>
>> The 16F88 has a USART and I use a triple inverter for a 0-5V RS232 link. It
>> does require a conversion cable (USB to DB9) but that's pretty simple. The
>> USB version uses Silicon Lab's CP2102 which is a better (and much smaller)
>> single chip USB-serial bridge that only requires a couple of bypass caps.
>>
>> The passives are 805 size which I think is the smallest that can be hand
>> soldered (even by a lame, spastic geezer like me) but it's easier to do all
>> of the SMT soldering in a toaster oven. There's probably no way the CP2102
>> can be hand soldered.
>>
>> The completed boards should cost in the $12-17 range.
>
>Very cool!