It’s been a while again, happy new year to everyone and I hope that you all enjoyed a wonderful festive season. I revised my circuit again and tested the relay functions before creating the board again. Reason being that I accidentally bought PNP transistors rather then NPN transisistors. Here are the circuit diagrams for relay configurations using either a PNP transistor:
or a NPN transistor.
Apologies that it is on paper at this stage, I will create the circuit diagrams using Eagle CAD some time and then post it. I’ve tested the circuits by soldering some wires onto my surface mount components to breadboard it out:
Messy but working.
Tidied it up a bit and looking nice and working 🙂 Then it was time for making the board:
Front and back of board.
I then started creating the board.
Used some flux to solder the entire board and I think it came out pretty good. 🙂
and finally the shield fitted perfectly into my Arduino UNO yeay (“,)
I fitted everything together then and it looked good
Everything was working well and then all of a sudden the display wasn’t working anymore ugh. Fault finded the hardware to try and find what was wrong with it and it took me quite a while a day and a bit but finally found out that there was a short circuit between some of the wires on the back of the display. I redid the wiring that was bridged and then used the glue gun to glue the wires to ensure that a short circuit won’t happen again. Joyous moment. While fault finding I was playing around and testing the board with my Arduino compatible Nano V3 and everything was working nicely.
I then noticed that my temperature reading was totally bogus so I thought that my temperature calculation was wrong. So I tested it the following morning but as soon as I applied heat to the sensor there was no difference to the reading. I then checked for any bridges between the tracks but there were none. So I’ve removed the IC to breadboard it out to test whether my connections were correct or not but then I managed to break off on of the pins of the IC, great 😦 and obviously there were’t stock in Cape Town, or in Johannesburg for that matter (i.e. nothing in South Africa) so I will have to wait 4 – 6 working days to have two replacement ICs delivered (One for spare). Once I receive it I will put it on a SOIC 8 to Dip prototyping board that I will create to test the circuit to find out whether I damaged the IC when I initially soldered it on or whether my circuit is incorrect. Don’t think that my circuit is incorrect since I based it on the Ultimaker design which is the example out of the datasheet. But lets see what happens when I receive the replacement ICs. So more waiting time. I will then also have to refine the programming but I am thoroughly fed up with this project at the moment so I’m hoping to be able to finish it as soon as possible but I will see how it goes.
I’ve uploaded a video to Youtube to display the interface of the unit a while back but haven’t listed a link to it as yet, so if you want to go have a look, you can go check it out here. So I hope to give you all an update again as soon as I have the replacement AD597 integrated circuits.