How to test a propeller without the serial connection ?

Jonathan Holle

I'am totally new in propeller use. I'am making an hexapod and I would like to make a servo controller with that chip. But, I can't communicate with it, the propeller tool say : "no propeller chip found"; my board seems to be ok and for the serial connection I use what is recommended by parallax (2N3904 & 06) so I think that the problem comes from the chip ... so my question is how to test it without pc connection ?

Voltages I got are :

P0 to P27 : 0,85v
P11 (resN) : 3,25
P12 (Vdd) : 3,25
P28 : 3,20
P29 : 3,20
P30 : 3,20
P31 : 2,70

Are these voltages ok ?

heater

One way would be to have a known good program in an EEPROM. Something that flashes some LEDS or perhaps even transmits through the Programming port to the PC.

Without that you are down to tracing what goes on with your serial port connection.

Without any scopes or test equipment I always resort to attaching a LED and resistor to significant points on the circuit and seeing if anything happens. For starters you will want to see if your Prop is getting a reset from the PC. So put a LED on the reset pin. Then you will want look for activity on the tx and rx pins. And so on.

I started out with the Prop with almost nothing more than a DIP Prop, power supply components and that transistor serial line circuit connected to a USB serial adapter. Not even an xtal or EEPROM so I know you can make it work if you check everything thoroughly and probe around enough.

Unless the Prop is really dead, which perhaps might become obvious as you probe around.

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For me, the past is not over yet.

Leon

It's useful to have a second chip.

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Leon Heller
Amateur radio callsign: G1HSM

Jonathan Holle

Good idea for the led !

So on the serial side :
- reset is powering off the led
- nothing on rx
- tx is powering off the led

exactly the same thing on the ttl side ...