Four Letter pHat with a Rasberry Pi 1

I have an old Raspberry Pi 1 and would like to turn it into an alarm clock. Step 1 is hooking it up to a four letter phat but, put simply, I’m utterly out of my depth. Can it be done? Has it been done?

Naturally, the next step is to hook up a button to snooze and cancel alarms. The buzzing will just be done using the sound out.

Thanks in advance for any help.

The four letter pHat pinout is here

It’s designed for a Pi with the 40 pin GPIO. I do believe the one you have only has the 26 pin GPIO? Might still be doable as the extra pins used are all grounds. I think I’d just buy a Pi Zero W to make life easier, as it will for sure work with that, and the Zero W is inexpensive.

You will need Internet access to keep the time accurate / updated. The Raspberry PI doesn’t have a Real Time Clock. Or add a Real Time Clock module

I’m not saying it can’t be done, just throwing some options out there. You will have to check the 26 pin pinout, if thats what you have, to see if the correct pins line up with those on the four letter. If its a Pi witha 40 PIN header then it should be doable with out too much fuse. Buster is backwards compatible with all previous model Pi’s. Or so I’m told.

Thanks. I’ll look into that. I was hoping to connect the hat to the pi using jumper wires so I could package the whole thing up in some box or other and without blocking off the remaining pins. That would in theory mean id didn’t matter if the pins don’t line up. I’ll give it a go and see what happens anyway.

Thanks. I was aware of the time problem but had planned on using a small usb wifi stick to get time updates from the net. I figured that would also be how I accessed it to set the alarm time. However, I might look into a breakout if that doesn’t work.

Truth is, I am terrible for no wanting to bin obsolete kit and need a use for this old Rasberry Pi 1.

I think its doable, with a little work. No harm in trying, as long as your careful and double check your jumpers etc before powering up, no harm should come to the hardware. And if you can’t make it work go to plan B, or C etc.
It’s nice to have options to fall back on so I try to mention those when I can.

Once again, thanks. After many failed attempts, mainly because I didn’t really understand the pinout diagram doesn’t make the ground very clear. It’s now working very happily.

Your not the first to miss a ground pin. They may need something more than the small black blob to designate a ground pin in use. On the Pi all the grounds on the GPIO header are linked together. On the Hat or pHat thats not always doable. You’d need more layers to the circuit board and that increases the cost. Assuming its going to be plugged into the Pi’s GPIO, the Pi will link them all together for you. Go with jumper wires and you have to sort out which ones are used and wire them all up.

Anyway, congrats and well done, have fun… =)

1 Like