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Feeler - Touchscreen OBC with Megasquirt CAN interface, extra sensors, outputs, etc.

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    #16
    Originally posted by Panici View Post
    Ah, I keep forgetting how much power the Teensy processor has to work with. Much easier to implement in software so that it's fully configurable.
    Recursive filter can be done pretty computationally efficiently too! Adding filter poles (sharper cutoff) increases computation, but in the case of PID control I want to minimize phase shift so I stick with 2 poles. You need two 3-element arrays to store recursive data, and you do a few additions and multiplications and one division each time around to update the loop. For example, here's the code for a 2-pole Butterworth low-pass for 8Hz cutoff at 50Hz sample rate.

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      #17
      Slight delay on PCB revisions discussed previously, and therefore a slight delay in placing the order (got sidetracked working on my VGT control algorithm). As mentioned, I'm not an electrical engineer, but figured out how to use some of their tools with no formal training - a dangerous combo!

      I've been using this questionable skillset at my job to design some prototype PCBs for battery-powered IoT devices, with several iterations done by this point. This is an application in a very hard environment (freight railroad), albeit with very little in the way of EMI. They have been working great in the field, but to scale up to higher volume we've hired a design firm to review the current PCB design and either suggest revisions or redesign from scratch. Overall, I apparently did a decent job, but they had several "best practices" type suggestions to improve long-term durability, decrease power-supply noise, etc. Things like "if an IC pin uses multiple bypass capacitors, put the smaller one closer to the pin." Super helpful for me, and I will be including the suggestions in the revisions to the touchscreen OBC board design before I place the order.

      Goal is to make the revisions and order the boards before the end of the weekend. I've also ordered 3 full enclosure kits (enclosure, bulkhead connector header, etc.), as well as 15 bulkhead connector headers. The bulkhead connector is the part that's super difficult to find in stock, and I suspect the 3 full kits I ordered were not actually in stock as claimed by the seller. But the 15 hard-to-get connectors are on their way and should be in-hand very soon.

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        #18
        Oh! Apparently the website did not lie, just got a shipment notification for the 3 full enclosure kits! Definitely lights a little bit of a fire to get PCBs ordered!

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          #19
          The service interval lights in my car are going to be converted to shift lights. I already have the board to do so ( I've had it for 2 years now, lol being lazy) Would this be something you could do as well to work hand in with your touch screen or maybe a new thing all together. Just a thought. There is only one company I think actually doing it right now.
          https://www.e30ig.com/#1thing

          88' Seta 2.7i

          https://www.r3vlimited.com/board/for...430-my-88-seta

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            #20
            Originally posted by It's Soda Not Pop View Post
            The service interval lights in my car are going to be converted to shift lights. I already have the board to do so ( I've had it for 2 years now, lol being lazy) Would this be something you could do as well to work hand in with your touch screen or maybe a new thing all together. Just a thought. There is only one company I think actually doing it right now.
            https://www.e30ig.com/#1thing
            Whoa cool! I think that should be doable in several different ways. Do you know how I can find more details on how to program the set points or installation instructions or something? That might help clue me in on how it works.

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              #21
              Originally posted by mikey.antonakakis View Post

              Whoa cool! I think that should be doable in several different ways. Do you know how I can find more details on how to program the set points or installation instructions or something? That might help clue me in on how it works.
              https://www.e30ig.com/Installation%2...0manual_v3.pdf

              88' Seta 2.7i

              https://www.r3vlimited.com/board/for...430-my-88-seta

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                #22
                Bulkhead connectors arrived. They are keyed so you can't mix them up:

                Untitled by Mikey Antonakakis, on Flickr

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                  #23
                  Originally posted by mikey.antonakakis View Post
                  Bulkhead connectors arrived. They are keyed so you can't mix them up:
                  Pretty fancy!
                  My Build Threads:
                  '87 BMW E30 325is Turbo
                  '86 BMW E28 535i
                  '98 BMW E36 328i
                  '90 Mazda NA Miata Turbo
                  '04 Jeep TJ
                  '05 Yamaha R6

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                    #24
                    In addition to those 15 bulkhead connectors, I ordered 3 full kits (enclosures, bulkhead connectors, harness-side connectors, pins, etc) from a different supplier. Two of the three kits are missing a major component, lol. Honestly looks like someone raided the kits to fill orders for individual parts.

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                      #25
                      Untitled by Mikey Antonakakis, on Flickr

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                        #26
                        Originally posted by mikey.antonakakis View Post
                        Image
                        Certainly looks like a quality enclosure and connector setup.
                        My Build Threads:
                        '87 BMW E30 325is Turbo
                        '86 BMW E28 535i
                        '98 BMW E36 328i
                        '90 Mazda NA Miata Turbo
                        '04 Jeep TJ
                        '05 Yamaha R6

                        Comment


                          #27
                          PCB design updates well underway. Kind of a lot to it, so far I have the schematic updated and I still need to redo the actual layout. But, I am having a design review today with the design firm that's helping with the PCBs I've done at work, so their recommendations will get rolled into this one.
                          Oh, it's getting a 3-axis accelerometer, too (ADXL362, +/-8g max). No gyro/magnetometer on this one - I haven't found any with good analog signal processing before they digitize it. Gyro would really only be helpful if you really wanted to record yaw rate.

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                            #28
                            Originally posted by mikey.antonakakis View Post
                            PCB design updates well underway. Kind of a lot to it, so far I have the schematic updated and I still need to redo the actual layout. But, I am having a design review today with the design firm that's helping with the PCBs I've done at work, so their recommendations will get rolled into this one.
                            Oh, it's getting a 3-axis accelerometer, too (ADXL362, +/-8g max). No gyro/magnetometer on this one - I haven't found any with good analog signal processing before they digitize it. Gyro would really only be helpful if you really wanted to record yaw rate.
                            This project has me hyped!
                            My Build Threads:
                            '87 BMW E30 325is Turbo
                            '86 BMW E28 535i
                            '98 BMW E36 328i
                            '90 Mazda NA Miata Turbo
                            '04 Jeep TJ
                            '05 Yamaha R6

                            Comment


                              #29
                              Board revision finished, maybe. Need to go back and double-check some stuff, make sure I'm not forgetting anything. I think I may order 15 of these to start.
                              I will have to order the VR sensor signal conditioner IC separately and solder by hand. Nothing spells fun like 0.5mm pitch surface-mount soldering!

                              Capture by Mikey Antonakakis, on Flickr

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                                #30
                                Order placed for 15 PCBs! Should have in 2 weeks (maybe sooner).

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