Thursday, June 11, 2020

Day 126, 127 - Pendleton, OR

Wednesday (126) - This morning, we finished the Pendleton Riverwalk By starting from the north end of town. It turned out to be only ¾ mile to our last turnaround point so we kept walking a bit further. After all, we have to get our miles in (the June Apple Watch challenge). I took this picture of the wall along the walkway. Obviously, they must not want people to sit here.

After our walk, we picked up groceries at Walmart. Even fewer people with masks on than last week.

I finished “packaging” the board and sensors for the wet bay. One sensor will be Gorilla taped to the fresh water tank and covered with a layer of close cell foam. A second sensor is simply measuring the air temperature behind the drain. I just want to know if that area ever gets anywhere near freezing. I needed to add a buck converter to provide 5VDC. I tapped into the bay convenience light for power. I received the logic level converters today. I’ll play with that tomorrow. And I ordered NPN Darlington transistors which could provide the same functionality as the MOSFET as far as LED dimmer using PWM.

A few months ago, I posted that the ground cable for the intake grid heater seemed to be missing. I added a temporary cable so the engine would start. Further research showed that there are two grid heaters in the intake manifold. One each for three cylinders and they are wired in series. It appears that one of them is burned out or something and it is the one that has the ground connection. One more thing to fix...

Thursday (127) - The wet bay temperature sensors are finally installed. This is surprising since this was one of the first boards I had assembled. But, I was needing a box so the board was just duct taped onto the fiberglass and powered off an old phone charger for almost a month. I also created an alarm if the outlet temperature drops near freezing.

Now for something different. A new direction for control of two LED recessed lights. Today, I received some Darlington NPN transistors (TIP120). The two 12vdc LED bulbs are only 1.8watts so they draw around 300ma total. This is about 20x the current output of the GPIO pins on the ESP32 so you need something to boost the current. I used a 1k-ohm resister to limit current into the base of the TIP120 From the ESP32. The collector was connected to the ground side of the LED and the emitter was connected to chassis ground. The other side of the LEDs are connected to 12vdc. This worked great. From Home Assistant I could turn the light on/off and vary the brightness. I’m using an ESP32 for this since it does PWM in hardware as if it really matters. It’s been quite a while since I used discrete components such as this transistor. Maybe 30-40 years.

I connected a wire from one of the GPIO pins that support “touch” and created an automation to toggle the light on/off. The challenge now is running a wire within the cabinet shelf to reach the second light fixture. And possibly using a single touch sensor for both on/off and dimming. Hmmm. A project…

8 comments:

Bluekat said...

Welcome to the boardwalk, please move along... 😆

redlegsrides said...

Intake grid heaters....similar to glow plugs?

Lynne Goebeler said...

I find it disturbing that despite cases climbing again, people seem less inclined to stay safe. Sad.

RichardM said...

This section of the walkway is next to the huge fields and stadiums for the Pendleton Roundup, a huge event for this town. Maybe they don’t want people watching from the walkway.

RichardM said...

Similar. Glow plugs are used in Diesel engines with prechambers. Non-prechamber engine such as the Cummins and Cat engines use a heater in the intake manifold to heat the intake air to help combustion with a cold engine.

RichardM said...

I think some states may be rethinking their decision to open up as much as they have. Even though I whine about Alaska’s policy, it is a step in the right direction.

SonjaM said...

It looks like we are out of the woods with regards to the virus, however people are still requested to wear face masks in shops and public transportation. And each and everyone does it. We Germans are very weird this way...

Lynne Goebeler said...

I agree, Richard. The increase is scary.