Marry Xmas to all :slight_smile: I've installed and tried today this mcp23017chip node , but it says: TypeError: Cannot read property 'setBit' of null How can I debug it further, what could be the problem? Can I see somewhere the source-code of this node? My guess is: it can only handle the de…

Do you mean that with them configured as inputs the pin is pulling low? What external components have got connected to the output?

Someone with more micro-electrical knowledge draw me this pic. (Paid him for advice.) [Raspberry-Pi_opto-in_relay-out_en] I think the 4.7k Ohm input resistors are not necessary between the opto-couplers and the IO chip, if I activate the built-in pull-up resistors.

Is this a Pi? You mustn't pull a pi gpio pin up to 5V, only to 3.3, and as you said you don't need it on outputs anyway, in fact in this application you should not have one at all. If you have pulled up to 5v through a 2.2k you may have blown the pin up, if not the pi itself.

The code is starting to feel safe now. No more NR crash, pin states are showing well: [kép] Also if wrong Bus number is set. (See nice red "! Error" text...) But there is still something wrong with bit masking, when I try to turn on/off: let ip1 = 0x00; if (bitNum < 8) { // first read current …

@Colin No. It's not a Pi. MCP23017 (i2c bus, 5V). Driving it through an AtTiny85 USB adapter with i2c-tiny-usb firmware. Tried Arduino Nano before that. (USB bus, 5V).

[image] PizzaProgram: But there is still something wrong with bit masking Found the error: if (bitNum < 8) { ip1 = _aBus.readByteSync(_addr, 0x12); } else { ip1 = _aBus.readByteSync(_addr, 0x13); ip1 = (ip1 << 8); // <<< that was missing ! }

I tend to use a set of functions that help me avoid typos... //Get bit function getBit(number, bitPosition) { return (number & (1 << bitPosition)) === 0 ? 0 : 1; } //Set Bit function setBit(number, bitPosition) { return number | (1 << bitPosition); } //Clear Bit function clearBit(number, bitP…

[image] PizzaProgram: No. It's not a Pi. You said earlier in the thread: [image] PizzaProgram: Also, I had exactly the same problem with "node-red-contrib-gpio" / Firmata using Arduino Nano boards. That's why I've started to modify this node The reference to node-red-contrib-gpio nod…

Help to make Help ... I still could not release the finished code, because wanted to add help to it. But nothing is shown. This is the code I've added to the .html file: <script type="text/x-red" data-help-name="mcp23017ouput"> <p>MCP23017 has 16 pins (0-15). Can be individually selected as in o…

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dceejay 6 January 2021 20:04 74

Presumably the name matches the node exactly?

Generally we don’t add a change list to the help as it doesn’t help use of the node. That is better off in the readme.

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