Improve build documentation (#523)

* added INA260 details

* added testing of INA260

* Added details of testing the INA260 in the README

* updated PCA9685 instructions

* typo

* specify wire length for roboclaws

Author: knickels

electrical/pcb/README.md

@@ -135,10 +135,12 @@ The INA260 daughter board is used for digital sensing of voltage and current, me
 
 **Option 1: If you have an INA260 daughter board, you should install that in footprint U1.**
 
-TODO: update parts here
-
 1. Attach an 8x1 female header to the 8 pins on the bottom side of the INA260 / U1 footprint, as seen in Figure 3.10
-2. Attach a 3x1 female header (cut from a longer Nx1 header) to the two pins on the top side of the INA260 / U1 footprint, as seen in Figure 3.10
+2. Solder the 8x1 male header pins to the INA260.
+3. Attach a 3x1 female header (cut from a longer Nx1 header) to the two pins on the top side of the INA260 / U1 footprint, as seen in Figure 3.14. You'll need to manually remove the center pin.
+4. Removce the center pin from a 3x1 male header pins, and solder to the INA260.
+5. Solder across pads A0 and A1 on the INA260 (to set it to use I2C Address 0x45)
+6. Install M2.5 x 12mm + 6mm standoffs to the side of the INA260 opposite the pins as shown in Figure 3.20
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/ina260_headers.png" height="300"> |
 |:-:|
@@ -154,11 +156,7 @@ TODO: need to update this discussion of bypassing U1 once the layout has been up
 
 Install a 0 ohm resistor in footprint R30, on the top side of the board
 
-### 3.6 Test INA260 installation
-
-TODO
-
-### 3.7 Install 5V bus regulator
+### 3.6 Install 5V bus regulator
 
 This is the power regulator for the 5V line, which powers all the motors.
 
@@ -172,7 +170,7 @@ Install 3 female headers for the daughter board, into U4. You will need a two 4x
 |:-:|
 | Figure 3.17: 5V regulator installed |
 
-### 3.8 Install 12V bus regulator U3
+### 3.7 Install 12V bus regulator U3
 
 Solder a 5x1 female header to the U3 footprint, and attach an appropriately sized standoff
 
@@ -190,7 +188,7 @@ TODO: specify standoff
 |:-:|
 | Figure 3.20: 12v regulator installed (2) |
 
-### 3.9 Install 3.3V bus regulator U7 and decoupling capacitor C7
+### 3.8 Install 3.3V bus regulator U7 and decoupling capacitor C7
 
 The 3.3V bus regulator is a linear voltage regulator and is physically much smaller - it comes in the same packaging as diode D1. Make sure to install the regulator in the correct direction as shown in figure 3.21.
 
@@ -208,7 +206,7 @@ Capacitor C7 is the decoupling capacitor for the 3.3v bus. Make sure to install
 |:-:|
 | Figure 3.24: Capacitor C7 installed |
 
-### 3.10 Install resistors R15, R24, and BJT transistor Q1
+### 3.9 Install resistors R15, R24, and BJT transistor Q1
 
 These form the circuit for the alert signal LED logic.
 
@@ -221,7 +219,7 @@ These form the circuit for the alert signal LED logic.
 | Figure 3.26: R15, R24, and Q1 installed |
 
 
-### 3.11 Test all voltage lines
+### 3.10 Test all voltage lines
 
 Test all the power buses/voltage lines using the test points on the far left side of the top side of the board (T7 through T12).
 
@@ -251,7 +249,7 @@ The silk screen right of each hole indicates what voltage each test point should
 | Figure 3.31: testing the PWR bus (main board power plane, after battery protection circuitry ) |
 
 
-### 3.12 Install PCA9685 daughter board in U2 footprint and capacitor C3
+### 3.11 Install PCA9685 daughter board in U2 footprint and capacitor C3
 
 :exclamation: Before continuing, make sure to disconnect the power supply from the previous step! You should not have the board powered on while installing components. :exclamation:
 
@@ -261,32 +259,42 @@ First you will need to install female headers on the motor board, for the PCA968
 - 6x1 female header
 - 3x 2x4 female headers
 
-You **may** use larger headers to fill all the holes in the U2 footprint, but it's not really necessary for the normal working configuration of the motor board. Attach these headers to the appropriate spots in the U2 footprint, as shown in figure 3.22.
-
-You will need to attach male headers to the PCA9685 daughter board, as shown in figure 3.23. Also, 5v power is provided to the PCA9685 through the two holes at the top of the U2 header. To connect these, I soldered 2 small wire leads on the PCA9685 daughter board, and then soldered them on to the motor board once I installed the PCA9685.
-
-TODO: update instructions with alternative to janky wire leads for PCA9685
-
-TODO: figure 3.33 is not very good
+You **may** use larger headers to fill all the holes in the U2 footprint, but it's not really necessary for the normal working configuration of the motor board. Attach these headers to the appropriate spots in the U2 footprint, as shown in figure 3.32.
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/PXL_20230418_053133239.jpg" height="300"> |
 |:-:|
 | Figure 3.32: U2 with female headers installed |
 
-| <img src="../../images/pcb_assembly/v2_0_1/assembly/PXL_20230418_054413269.MP.jpg" height="300"> |
+You will need to attach male headers to the PCA9685 daughter board, as shown in figure 3.33. 
+
+| <img src="../../images/pcb_assembly/v2_0_1/assembly/pca9685_headers.jpg" height="300"> |
 |:-:|
 | Figure 3.33: Male headers soldered onto PCA9685 daughter board |
 
+Also, 5v power is provided to the PCA9685 through the two holes at the top of the U2 header. You have a couple options for this.
+
+** Option 1 - Wires **
+To connect these, I soldered 2 small wire leads on the PCA9685 daughter board, and then soldered them on to the motor board once I installed the PCA9685.
+
+** Option 2 - 1x1 Pins/Headers
+The V+ and GND on the PCA9685 don't exactly line up with the GND_motor and +5V_motor pins on the Motor board, but are close enough you can make them connect with two 1x1 pins on the PCA9685 and two 1x1 headers on the Motor board, as shown in figure 3.34.
+
+| <img src="../../images/pcb_assembly/v2_0_1/assembly/pca9685_headers.jpg" height="300"> |
+|:-:|
+| Figure 3.34: Male headers soldered onto PCA9685 daughter board |
+
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/PXL_20230424_003801047.jpg" height="300"> |
 |:-:|
-| Figure 3.29: PCA9685 installed in motor board |
+| Figure 3.35: PCA9685 installed in motor board |
+
+Finally install capicator C3 as shown in figure 3.36.
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/c3_installed.png" height="300"> |
 |:-:|
-| Figure 3.29.1 : C3 installed |
+| Figure 3.36 : C3 installed |
 
 
-### 3.13 Install resistor R5 and capacitor C1
+### 3.12 Install resistor R5 and capacitor C1
 
 These are aids for the INA260, and can be left out if the IN260 is not used
 
@@ -304,13 +312,27 @@ Use an 8x1 female header for J20.
 |:-:|
 | Figure 3.31: Components installed, as viewed from top of board |
 
-### 3.14 Install resistors R2,R3,R4
+### 3.14 Test INA260 installation
+
+To test the INA260, you will follow https://learn.adafruit.com/adafruit-ina260-current-voltage-power-sensor-breakout/arduino, and connect an Arduino to GND, SCL, and SDA on J20.  You'll change the initalization step to
+```
+ if (!ina260.begin(0x45)) {
+```
+to account for the I2C bus address.  When you turn your power on, you should see something like this in the Arduino serial terminal:
+```
+Found INA260 chip
+Current: 85.00 mA
+Bus Voltage: 14456.25 mV
+Power: 1230.00 mW
+```
+
+### 3.15 Install resistors R2,R3,R4
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/r2_r3_r4.png" height="300"> |
 |:-:|
 | Figure 3.32: Components installed, as viewed from top of board |
 
-### 3.15 Install Roboclaw standoffs, headers, and capacitors
+### 3.16 Install Roboclaw standoffs, headers, and capacitors
 
 Now we'll add the parts for roboclaw footprints RC1, RC2, and RC3.
 
@@ -323,7 +345,7 @@ Finally, install the following capacitors for each RC footprint:
 - RC2: capacitors C2,C4,C9,C10 (figure 3.34). Install on the underside of the board.
 - RC3: capacitors C14,C16,C18,C21 (figure 3.34). Install on the top side of the board.
 
-Technically, you can install the capacitors on either side of the board, but it makes for a cleaner presentation if you install them where their respecit "C" labels are on the board.
+Technically, you can install the capacitors on either side of the board, but it makes for a cleaner presentation if you install them where their respective "C" labels are on the board.
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/rc1_pop.png" height="300"> |
 |:-:|
@@ -333,7 +355,7 @@ Technically, you can install the capacitors on either side of the board, but it
 |:-:|
 | Figure 3.34: C13,C15,C17,C20 and C14,C16,C18,C21 installed|
 
-### 3.16 Install motor supply headers J16,J17,J18
+### 3.17 Install motor supply headers J16,J17,J18
 
 Figure 3.35 shows how these should be installed. J16 on the top of the board is installed in the same way.
 
@@ -343,9 +365,9 @@ Make sure to orient the connector in the proper direction, as indicated in the i
 |:-:|
 | Figure 3.35: J17 and J18 installed, on bottom of board|
 
-### 3.17 Install 3x Roboclaw boards in footprints RC1, RC2, RC3
+### 3.18 Install 3x Roboclaw boards in footprints RC1, RC2, RC3
 
-First, wire the 6pos terminal block headers to the roboclaw boards, as indicated in figure 3.36.
+First, wire the 6pos terminal block headers to the roboclaw boards, as indicated in figure 3.36.  Cut the wires to about 5cm and tin the ends.
 
 Unless you have an older version of the PCB (v2.0.2 or earlier), wire the pins in the J16,J17,J18 headers directly to the pins on the corresponding side of the roboclaw - it is a direct 1-to-1 mapping all the way down, with no wires crossed. Use 16AWG wire (18AWG would also be fine)
 
@@ -361,29 +383,29 @@ Then install the 3 roboclaws in the RC1, RC2, and RC3 footprints. It doesn't mat
 |:-:|
 | Figure 3.37: Installing the roboclaw boards |
 
-### 3.18 Install capacitors C5,C6
+### 3.19 Install capacitors C5,C6
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/PXL_20230426_055549256.MP.jpg" height="300"> |
 |:-:|
 | Figure 3.38: Installing capacitors C5, C6|
 
-### 3.19 Install corner servo header J19, and capacitor C19
+### 3.20 Install corner servo header J19, and capacitor C19
 
 Make sure to install C19 in the proper direction, as shown in figure 3.39. One side of the capacitor has negative polarity indicators on it, that should be installed opposite the "+" sign on the footprint.
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/j19_c19.png" height="300"> |
 |:-:|
 | Figure 3.39: J19 and C19 installed (top of photo) |
 
-### 3.20 Install LED array U5
+### 3.21 Install LED array U5
 
 Make sure to align the slightly "chipped"/beveled corner of the LED array with the beveled corner of the U5 footprint, to have proper LED polarity
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/u5_installed.png" height="300"> |
 |:-:|
 | Figure 3.40: LED array U5 installed |
 
-### 3.21 Install drive motor headers J8,J9,J10,J11,J13,J14
+### 3.22 Install drive motor headers J8,J9,J10,J11,J13,J14
 
 | <img src="../../images/pcb_assembly/v2_0_1/assembly/IMG_0827.jpeg" height="300"> |
 |:-:|