This is by far the best deal in the world for embedded microcomputers.
http://www.mikroe.com/mini/stm32-m0/
32 bit ARM BASIC
$38 USD including DHL shipping from Zagreb.
There is nothing more compact and lower cost than surface mount on
both sides of the PC board.
Paul Lamar
Things they are a changing by the minute in the ARM world :)
I just received word that CoriDium free BASIC compiler may support
the Tensey 3.1 board.
https://www.pjrc.com/teensy/teensy31.html#specs
The MikroElect board requires the MikRo BASIC $250 pro compiler.
I deem that too much money to get wide spread interest.
==================================================
https://www.pjrc.com/teensy/teensy31.html#specs
12 Bit Analog Output
Teensy 3.1 has a proper analog output. You can always filter PWM, but
true analog output responds rapidly. The output is created by the stable
reference voltage, so it's doesn't vary if your power supply voltage
changes slightly. [Not to mention it is much easier to program than PWM. PL]
// Simple DAC sine wave test on Teensy 3.1
float phase = 0.0;
float twopi = 3.14159 * 2;
elapsedMicros usec = 0;
void
*setup*() {
analogWriteResolution(12);
}
void
*loop*() {
float val = sin(phase) * 2000.0 + 2050.0;
analogWrite(A14, (int)val);
phase = phase + 0.02;
if (phase >= twopi) phase = 0;
while (usec < 500) ; // wait
usec = usec - 500;
}
Simply use analogWrite() on the A14 pin for true analog output.
=============================================
Old message.
*******************************************************************
Subject: back up EFI Sat, 08 Feb 2014 04:33:43 -0800
This hardware trick keeps the injectors going even if the computer crashes.
It also greatly simplifies the PWM software.
I am thinking of implementing it on the ARM BASIC PC
board.
Here is a picture of the AD7203 DAC PC board layout.
The program places the pulse width digital data on the port and then
toggles the /WR pin. Then the program or the CAS triggers the 555
injector driver. That is all there is to it.
Very little processor overhead and no software bugs:) No timer interrupts.
You can think of this as a glorified 555 fuel injector system.
As long as you have power to it the CAS will keep triggering the
injectors.
One of these years microcomputer chips makers will build these in like
they did with my latched priority interrupts :)
Here is the final schematic.
We will see shorty how easy the ARM BASIC handles PWM.
******************************************************************
This Teensey 3.1 chip has a Digital to Analog output feature which further
simplifies my hardware PWM 555 solution and eliminates the expensive
analog to digital converter chip. This knocked me off my chair :)
THIS IS REALLY COMING TOGETHER AS THE MOST POWERFUL OPEN SOURCE EFI
AND AT VERY LOW COST!!!!!!! It will be super simple and small.
Paul Lamar
The Rotary Engine News Letter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net.
You Tube
http://tinyurl.com/beqqxas.
Copyright 1998-2013 All world wide rights reserved.
