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Forum Index : Microcontroller and PC projects : Help-Color Maxi+Freetronics relay driver
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| zcontrol Newbie  Joined: 14/09/2013 Location: AustraliaPosts: 7 |
HI Folks, I'm new to the maximite scene but have been playing in the retro computing scene for a while. I am currently trying to use the color maximite to control a model railway both for input and output. To help get things moving quickly, I invested in a Freetronics Arduino relay driver shield, plugged it into the maximite and have been trying to get it working to days with no luck. The first problem I had was not realising I had to set the SCL / SDA jumpers on the maximite board. Once I did that I could then send commands to the board via the I2CSend command and not recieve an error however, it does not appear that the board is actually doing anything. What I am expecting to see is a relay driver led come on when I send the corresponding relay code, but nothing. To be honest I am completely stuck and not sure what to do from here. The documentation for the board including sample C code can be found here: http://www.freetronics.com/pages/relay8-8-channel-relay-driv er-shield-quickstart-guide any help would be greatly appreciated and thanks in advance. |
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centrex Guru  Joined: 13/11/2011 Location: AustraliaPosts: 320 |
Probably a good idea to include your code so that we can see what you are doing. Are you using a external supply as recommended. Regards Cliff Cliff |
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| zcontrol Newbie Joined: 14/09/2013 Location: AustraliaPosts: 7 |
Hi Cliff, since I am not currently driving any relays I am using the internal power supply and the plug pack is supplying 1.5amps at 9v, which is plenty. As for the code: 10 I2CEN 100,1000 20 I2CSEND 32,0,1,128 30 Print MM.I2C when I run this I get a 0 which means the command worked, but the decimal value of 128 on line 20 should enable all the relays? The C code on the freetronics site for the Arduino version is a little more elaborate? |
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BobD Guru Joined: 07/12/2011 Location: AustraliaPosts: 935 |
That value of 128 in line 20 will only enable relay 8. If you want all on you have to add the values for each relay. You need a value of 255 for all relays. |
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| zcontrol Newbie Joined: 14/09/2013 Location: AustraliaPosts: 7 |
I did try 255 no go. irrespective of the value I add, non of the relay LED are lighting up. I even checked the physical voltage and nothing, so the board although it is ackowledging the command, its actually not doing anything with it. |
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jman Guru Joined: 12/06/2011 Location: New ZealandPosts: 711 |
Is there a circuit diagram for the shield ? I suspect that the LEDs are driven by the same power supply as the relays. So if the relays are not powered well you know the rest John |
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| zcontrol Newbie Joined: 14/09/2013 Location: AustraliaPosts: 7 |
Hi John, refer to the link above in the first post for a diagram. But please note that the shield defenitely has power, as the power LED is on, which means that it is ready to deliver power to the relays, assuming the board is instructed to do so! |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6100 |
The board has two power leds. Green for VCC which supplies the relays and the relay LEDs Blue for 5V supply. I don't see any 5V regulator so you need 5 to 24V for VCC and 5V regulated for the IC Both Green and Blue LEDs need to be on for a working board. Jim VK7JH MMedit MMBasic Help |
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| jman Guru Joined: 12/06/2011 Location: New ZealandPosts: 711 |
Yip I agree with Jim Stick 12VDC on connector JP6 and I am sure the LED's will spring to life :) John |
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| zcontrol Newbie Joined: 14/09/2013 Location: AustraliaPosts: 7 |
Jim and John, I can confirm that both the green and blue LED are lit and in fact I am getting an I2C return code of 0 from the above program which means I can successfully talk to the board, it just does not seem to actually switch the respective relays on. At this stage I have to believe this is a software issue although I have not completely ruled out the hardware. So to summarise: 1. Both LEDs are lit 2. I can successfully send I2C commands to the board 3. Board does not react as expected by switching on the respective relay I can only assume that I am not sening through the correct I2C command or command sequence. It would be great if someone could take a look at the Arduino code posted in the link above and come to some sort of conclusions regarding the commands that need to be sent via the I2C interface. |
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| jman Guru Joined: 12/06/2011 Location: New ZealandPosts: 711 |
Ok lets try this Run the code below Start: I2CEN 100,100 ' Enable I2C I2CAddr = &H20 ' this is the 23017 I2C address ' A2=A1=A0=0 <-> x100 000x Init23017: I2CSEND i2caddr, 0, 2, &H0A, &B10100000 I2CSEND i2caddr, 0, 2, &H0B, &B10100000 I2CSEND i2caddr, 0, 2, &H05, &B10100000 I2CSEND i2caddr, 0, 2, &H00, &B00111111 I2CSEND i2caddr, 0, 2, &H06, &B00111111 I2CSEND i2caddr, 0, 2, &H10, &B00000000 I2CSEND i2caddr, 0, 2, &H19, &B00000000 ' End of Init I2CSEND i2acaddr, 0 ,2, &H09, &HFF Pause 500 I2CSEND i2acaddr, 0 ,2, &H09, &H00 End Post the results Regards John |
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| zcontrol Newbie Joined: 14/09/2013 Location: AustraliaPosts: 7 |
John, my friend you are a genious. The code posted above enabled the LEDs for relays 7 and 8 briefly and then switched them off again. to be honest I was assuming that this line I2CSEND i2acaddr, 0 ,2, &H09, &HFF would enable all the relays, but then again I had no clue to begin with! Was the result what you expected? The good news is, you have figured out how to get the board to do something! |
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| jman Guru Joined: 12/06/2011 Location: New ZealandPosts: 711 |
Hi Glad to hear you had some success Try this code I2CEN 100,100 ' Enable I2C I2CAddr = &H20 ' this is the 23017 I2C address ' A2=A1=A0=0 <-> x100 000x Init23017: I2CSEND i2caddr, 0, 2, &H0A, &B10100000 ' Control Register Setup I2CSEND i2caddr, 0, 2, &H0B, &B10100000 ' Control Register Setup I2CSEND i2caddr, 0, 2, &H05, &B10100000 ' IOCON I2CSEND i2caddr, 0, 2, &H00, &B00000000 ' IODIRA I2CSEND i2caddr, 0, 2, &H09, &B00000000 ' GPIOA I2CSEND i2caddr, 0, 2, &H10, &B00000000 ' IODIRB I2CSEND i2caddr, 0, 2, &H19, &B00000000 ' GPIOB Print MM.I2C Start: I2CSEND i2caddr, 0, 2, &H0A, &B10101010 Pause 1500 I2CSEND i2caddr, 0, 2, &H0A, &B01010101 Pause 1500 I2CSEND i2caddr, 0, 2, &H0A, &B00000000 GoTo Start Led's should alternate 10101010 / 01010101 I have attached a link to the 23017 datasheet for you to take a look at MCP23017 Datasheet Regards John |
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| zcontrol Newbie Joined: 14/09/2013 Location: AustraliaPosts: 7 |
OK that did it, thanks John, I can start doing some useful stuff now! And thanks for the datasheet reference, I was wondering how you got to be so knowledgeable :) In my case without your guidance no amount of datasheets would have helped, hehehe. Thanks Again. |
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