[Solved]Python Relay Expansion help

[A Former User]

This post is deleted!

[SYLVAIN MAILHIOT]

Is your expansion working if you use the console ?

[Lazar Demin]

@Rudy-Trujillo
To install everything required:

 opkg update 
 opkg install python-light pyRelayExp

And here is a short script that just tests the functionality:

from OmegaExpansion import relayExp
import time
import sys

# check the arguments
if len(sys.argv) != 2:
	print 'ERROR: expected addr offset:'
	print sys.argv[0], '<addr offset>'
	exit()

addr = int(sys.argv[1])

print 'Starting to use relay-exp functions on addr offset', addr

relayExp.setVerbosity(0)

# check initialization
ret 	= relayExp.checkInit(addr)
print "checking if initialized: ", ret

# initialize the relay-exp
ret 	= relayExp.driverInit(addr)
print "Result from relayDriverInit: ", ret
if (ret != 0):
	exit()

# check initialization
ret 	= relayExp.checkInit(addr)
print "checking if initialized: ", ret
time.sleep(1)


# set channel 0 to on
ret 	= relayExp.setChannel(addr, 0, 1)
print "Result from relaySetChannel: ", ret
if (ret != 0):
	exit()
time.sleep(2)

# set both channels to on
ret 	= relayExp.setAllChannels(addr, 1)
print "Result from relaySetAllChannels: ", ret
if (ret != 0):
	exit()
time.sleep(2)

# set channel 0 to off
ret 	= relayExp.setChannel(addr, 0, 0)
print "Result from relaySetChannel: ", ret
if (ret != 0):
	exit()
time.sleep(2)


print "Done"

I'll post examples for all three modules later this week!

EDIT: Note that the address argument that specifies the offset to add to the base address of 0x20. Follow the address table on the Wiki.

[A Former User]

This post is deleted!

[Lazar Demin]

@Rudy-Trujillo
Once the Relay Expansion hardware is initialized once, it will remain initialized. I'm guessing the screenshot above was not from the first time the script was ran? If that's the case, everything seems to be running correctly.
(You can make the driverInit call dependant on the checkInit return value to avoid unnecessary initialization in your real program)

Here's my output when I run it right after plugging in the Relay Expansion:

root@Omega-18C2:~# python relay-test.py 7
Starting to use relay-exp functions on addr offset 7
checking if initialized:  0
> Initializing Relay Expansion chip
Result from relayDriverInit:  0
checking if initialized:  1
> Setting RELAY0 to ON
Result from relaySetChannel:  0
> Setting both RELAYS to ON
Result from relaySetAllChannels:  0
> Setting RELAY0 to OFF
Result from relaySetChannel:  0
Done

In general, the functions return 0 to indicate success and 1 to indicate failure. The checkInit function is special, take a look at this section from the Relay Expansion Library wiki for more info.

[A Former User]

This post is deleted!

[Lazar Demin]

Small Update:
Example python code has been added to the i2c-exp-driver repo.

The examples are also linked in the wiki articles for the Relay, PWM, and OLED Libraries.

Edit: Updated the links

[Stephen Tunney]

@Lazar-Demin
Your link to the address table on the Wiki is a dead link. Can you update it please?

[Kit Bishop]

@Stephen-Tunney I may be wrong, but I think the link(s) you are looking for in relation to Relay, PWM and OLED python libraries are:

• https://wiki.onion.io/Documentation/Libraries/Relay-Expansion-Python-Module
• https://wiki.onion.io/Documentation/Libraries/PWM-Expansion-Python-Module
• https://wiki.onion.io/Documentation/Libraries/OLED-Expansion-Python-Module

[Stephen Tunney]

Awesomesauce!!! Thank you, @Kit-Bishop.