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….....................................--- HandCab WiFi Throttle – Part 5 ---
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Time to get into the main wiring.
Wire the decoder as shown above. Stick with the wire colors as shown in the schematic. Will make things much easier on you as we go on.
Hopefully once the throttle software is completed you will be able to switch between the throttle lever on the control stalk to the encoder throttle control and back and forth. At times the encoder which will be capable of changing speeds quicker than the more realistic acting throttle lever might be preferred.
On an earlier page I made and used PCB solder pads for the voltmeter and LED circuits. I find these easy and quick to make and use but...
…. an other option is to use perfboard like Lee used in the image above. Your choice, pick which works best for you.
Make up another solder pad as shown above. There will be a lot of negative and positive wires soldered to it going forward.
Wire the ESP32 3v and negative posts to the solder pad that was just made. I used 22 gauge but smaller might work.
Wire a negative from the negative solder pad (above ESP32) to the middle of the PCB for the battery LED indicators and then on to one side of the PCB (bottom in the image above) for the voltage meter circuit. Wire a red wire from the top side of that PCB to the positive side of the main solder pad above the ESP32. Wire a blue wire from the center of the voltage meter PCB to pin 36 of the ESP32 (last pin on the one side).
Note: the ESP32 pins are not numbered in a sequential order. Refer again to the color coded schematic (you have printed it out right?)
Also solder the wires for the Encoder at this time as shown above and on the schematic.
With a wire pre-tinned and the ESP32 pre-tinned soldering wires to the ESP32 is simple and quick. Bend the wire 90 degrees above the tinned end....have the iron tip clean with a small drop of solder on it....hold the wire against the side of the post....drag the iron along the wire and post and if the iron is hot the solder should flow right along the post and wire and they will be soldered together in a neat compact solder joint.
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Connect the top with all of the screws but then take the two on the right side back out and make another solder pad for that side.
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Be sure to also make the isolation cut on the bottom to isolate the positive pad from the throttle pad on the top.
You will come back in a bit and solder wires from the throttle, brake and reverser pads to the correct pins on the ESP32. You can see above how the solder pads allow one to connect a lot of wires in a small place. As the solder builds up on the pad by only soldering one wire at at time put a larger drop of solder on the iron and have it as hot as possible. The solder on the iron will flow onto the wire and solder that is below it. If you try and heat the pad until the solder flows on it when it does flow (takes a while) some of the wires will probably pop off. One can also twist some of the wires together and solder them as a group.
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Disregard the solder pad on the image above. I used it in the first throttle build but you don't need it for the build.
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NOTE: The first wire is soldered to the first hole in. The end holes are not used.
I found it easiest to solder the wires to the keypad with the keypad in my vise. I could then hold the wire in with the insulation butted up against the keypad and make a quick solder joint with a small drop of solder on a 'clean iron tip' and I had put liquid flux on the solder points first.
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It is time to attach the middle case part to the top of the case with the control stand on it. Use #4-40 screws of the right length (I think I used #4-40 x 1/4”). Make sure they aren't too long and end up puncturing the case top coming out on the top side.
Earlier you should of determined if you needed the thinner or thicker bracket that presses against the bottom on the keypad. You can use a small length of double sided tape to hold it on the middle case's cross-member while screwing the case parts together.
The wires for the keypad should be pushed up along side the ESP32 on the side they will be soldered to (see next image).
Solder the keypad wires to the ESP32. Getting close to the end of soldering wires to the ESP32 (one of the quicker things to do in the build). Only have the wires from the 7 button switches to go along with the control wires from the pots.
For the whole build of this throttle go ( HERE ).
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