Re: Very cheap, 24 cent microprocessors. #firmware #i2c

AC9NM - Jerry Ponko

If you get some low temperature solder paste (such as Maker Paste ) and a hobby/craft heat gun and most multi-pin surface mount parts shouldn't be a problem.  At $6.95 for a little tube, it may seem expensive but you'll be using tiny dabs of it with a pin. Another way to deal with them is to either buy or make some breakout to 8, 16 dip pcbs and you can then use 2.54mm pin sockets headers on your circuit boards.

Jerry, AC9NM

On 3/5/20 9:38 AM, Jack, W8TEE via Groups.Io wrte:
Mornin' Ken:

I agree with your statement, and that's really sad because most hams could easily do SMD parts. Farhan uses 1206 parts and even my 76 year old eyes and hands can work with them. They should invest $1.25 in an SMD practice kit (e.g., eBay 283799161850) and give it a try. I'll bet they would be surprised at how easy it is, plus kits using SMD parts are likely less expensive than a thru-hole equivalent.

Jack, W8TEE

On Thursday, March 5, 2020, 9:27:21 AM EST, Ken Hansen <ken@...> wrote:

Interesting, but from what I saw these are surface mount parts, many hams are put off by projects that rely on such parts.

Ken, N2VIP

On Mar 4, 2020, at 23:05, Tom, wb6b <wb6b@...> wrote:


I stumbled upon these microprocessor chips at just $0.24 each. What is really compelling about these chips is they have an 8 channel A/D converter with 12 bit resolution. That is better than the Nano at 10 bits. And the A/D is many times faster.

Seems great where you would want to measure things in your radio, be able to digitize them and send the readings to other parts of the system, such as the Raduino. With a little bit of control functionally mixed in.

Looks like the old time 8051 processors did not die, they still live on in inexpensive yet faster processor chips. I suppose there must be a warehouse of assembly code and possibility C code piled up on-line or elsewhere for these 8051 and derivative chips.

The chip has a built in factory trimmed 24mhz RC clock oscillator and a 10Khz RC oscillator for a low power mode. And a UART, assorted timers, GPIO and such. Looks like a battery (or other power supply) and maybe a small power bypass cap and you are good to go. 

Looks like a great chip for things that could be cobbled together with a few lines of code and seemed so trivial that using a microprocessor chip seems overkill. (Although it will handle way more than just a few lines of code.)

Too bad it does not have a built in temperature sensor (I guess they have to leave something out for 24 cents). You could have used it to control your cooling fan and it might have been cheaper than a thermistor. I might make a dimmable red led light for the spotter scope graticule on my telescope. Hard to think of a much more trivial and previously though to be overkill project for a microprocessor. 

I ordered some for my parts box along with a $25 development board, with a built-in programmer, that looks like I can use to develop and program the chips with.

Hopefully there will be open source and manufacture supplied tools to develop and upload the programs, without needing expensive commercial development tools. I believe that is the case. It should be possible to cobble together a free toolchain if it does not already exist. If anyone else has done development with the various recent 8051 derivative chips, it would be interesting to hear about your thoughts. 

It will be fun to go back in time and visit to the good old days of very simple chips and instruction sets; but at the same time be modern.

I discovered this chip because I bought one of the WiFi relay modules on eBay and besides the WiFi module (ESP-01), this chip (actually the older version) was used to turn the relays on and off based on hex codes sent over a serial link.

I'll know more when everything arrives and can play with the development board.

Tom, wb6b

Jack, W8TEE
Jerry AC9NM

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