Uploaded November 2025 | Updated September 2026, 3 weeks ago
I've been quiet on Youtube recently, but not for lack of work on the boat! This video shows what I've been up to. With the significant help of Patrons and friends, I have four new PCBs on order. These will be the helm control boards for Mermaid's Rest.
In the coming videos, we'll assemble and start writing the code. This video shows how the boards will work, at a high level, and some of the challenges I had to overcome. More than anything, all I've learned to make these boards have a chance of being reliable over the journeys to come.
A super huge and special thank you to the folks on Patreon. Their knowledge and patience is beyond description!
-=] Patreon:
- patreon.com/c/TheDigitalMermaid
-=] Channels that have Helped Me;
* @ProjectBrupeg
* @OffGridGarageAustralia
* @AcornToArabella
* @BillCarlson
-=] References;Charlieplexing
- en.wikipedia.org/wiki/Charlieplexing
Adafruit Charlieplexer
- adafruit.com/product/2946
ST Nucleo-C092RC
- st.com/en/evaluation-tools/nucleo-c092rc.html
Lumissil IS31FL3731
- lumissil.com/assets/pdf/core/IS31FL3731_DS.pdf
Scotopic (Night) Vision
- en.wikipedia.org/wiki/Scotopic_vision
ST STM32C092KCT6
- st.com/resource/en/datasheet/stm32c091cc.pdf
STLINK-V3SET
- st.com/resource/en/data_brief/stlink-v3set.pdf
NMEA 2000 / N2K
- en.wikipedia.org/wiki/NMEA_2000
GitHub - Mermaid's Rest - Full Boards
- github.com/digimer/Mermaids-Rest/tree/main/Full%20Boards
CC BY-NC-SA 4.0 - Attribution-NonCommercial-ShareAlike 4.0 International
- creativecommons.org/licenses/by-nc-sa/4.0/deed.en
GPLv3 - GNU General Public License v3
- gnu.org/licenses/gpl-3.0.en.html
Bill of Materials - Google Sheets
- docs.google.com/spreadsheets/d/1s2RV25Aqq35Ps_foCP7-pKksEfrfetYYAbn-AQ_H0tk/edit?usp=sharing
Cassette Futurism
- aesthetics.fandom.com/wiki/Cassette_Futurism
TI MAX3232EIPWRQ1
- ti.com/lit/ds/symlink/max3232e-q1.pdf?ts=1736232244138
FD CAN bus
- en.wikipedia.org/wiki/CAN_FD
ST M24C64-RMN6P - 64 KiB EEPROM
- st.com/resource/en/datasheet/m24c64-f.pdf
I2C (Inter-Integrated Circuit) Bus
- en.wikipedia.org/wiki/I2C
SPI (Serial Peripheral Interface)
- en.wikipedia.org/wiki/Serial_Peripheral_Interface
GPIO (General Pupose Input/Output)
- en.wikipedia.org/wiki/General-purpose_input/output
Gerber File Format
- en.wikipedia.org/wiki/Gerber_format
KiCAD
- kicad.org
Ep. 98 - The Motors Spin!
- youtube.com/watch?v=ylXH46X1Iwk
ST STM32G474RET3
- st.com/en/microcontrollers-microprocessors/stm32g474re.html
MCP4726 DAC
- ww1.microchip.com/downloads/en/DeviceDoc/22272C.pdf
4N25 Opto-isolator
- vishay.com/docs/83725/4n25.pdf
JTAG
- en.wikipedia.org/wiki/JTAG
-=] Chapters
0:00 - A Small Diversion That Wasn't Small. At All.
2:00 - Feature Creep Is A Thing / Patreon Thanks
3:40 - Scotopic vision and Red LEDs
4:27 - Well, Why Don't You Just...
5:58 - Power Isolation On A PCB
7:06 - Everything Is Open Source, Hack Away!
8:16 - So Many Voltages
10:23 - Cassette Futurism and Serial Ports
11:47 - MCU, NMEA2000/CANbus, EEPROM
12:58 - The I2C and SPI Busses
14:04 - GPIO Pin Protection; When Wires Are Antennas
16:12 - Pull Up and Pull Down Resistors
17:51 - Schematics And NetNames
19:55 - High-Level Overview of Charlieplexing
23:19 - PCB Routing; The Compass Rose PCB
26:44 - Putting Part On Both Sides Of The PCB; Why?
28:36 - DRC; Design Rule Checked - The Most Annoying Good Thing
29:14 - KiCAD Has A Great Community
29:49 - 3D Renders!
31:47 - Thermal Management
32:47 - Fixing A Small Mistake; Schematic to PCB
35:13 - The Next PCB; The Main Control Unit
39:57 - Optoisolators; They're Basically Magic
40:39 - Accurate Indication With Coarse LEDs
42:10 - D-Sub Connectors. SO MANY D-SUB!
45:32 - E-Stop Logic
46:31 - My Diesel Is Gone, I Got A New Diesel
49:01 - The MCU PCB And Field Repairability
50:51 - MCU Controlled Relays And Inductive Loads
52:24 - Battery Display Board; Electric Propulsion to ABYC Standards
54:58 - Relay Unit; Super Efficient Digital Switching!
1:00:40 - What's Next?
-=] Music Attribution
Eighties Action by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0
Source: incompetech.com/music/royalty-free/index.html?isrc=USUAN1100243
Artist: incompetech.com
Touchpoint by Audionautix is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0
Artist: audionautix.com
Inner Journey by Audionautix is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0
Artist: audionautix.com
I've been quiet on Youtube recently, but not for lack of work on the boat! This video shows what I've been up to. With the significant help of Patrons and friends, I have four new PCBs on order. These will be the helm control boards for Mermaid's Rest.
In the coming videos, we'll assemble and start writing the code. This video shows how the boards will work, at a high level, and some of the challenges I had to overcome. More than anything, all I've learned to make these boards have a chance of being reliable over the journeys to come.
A super huge and special thank you to the folks on Patreon. Their knowledge and patience is beyond description!
-=] Patreon:
- patreon.com/c/TheDigitalMermaid
-=] Channels that have Helped Me;
* @ProjectBrupeg
* @OffGridGarageAustralia
* @AcornToArabella
* @BillCarlson
-=] References;Charlieplexing
- en.wikipedia.org/wiki/Charlieplexing
Adafruit Charlieplexer
- adafruit.com/product/2946
ST Nucleo-C092RC
- st.com/en/evaluation-tools/nucleo-c092rc.html
Lumissil IS31FL3731
- lumissil.com/assets/pdf/core/IS31FL3731_DS.pdf
Scotopic (Night) Vision
- en.wikipedia.org/wiki/Scotopic_vision
ST STM32C092KCT6
- st.com/resource/en/datasheet/stm32c091cc.pdf
STLINK-V3SET
- st.com/resource/en/data_brief/stlink-v3set.pdf
NMEA 2000 / N2K
- en.wikipedia.org/wiki/NMEA_2000
GitHub - Mermaid's Rest - Full Boards
- github.com/digimer/Mermaids-Rest/tree/main/Full%20Boards
CC BY-NC-SA 4.0 - Attribution-NonCommercial-ShareAlike 4.0 International
- creativecommons.org/licenses/by-nc-sa/4.0/deed.en
GPLv3 - GNU General Public License v3
- gnu.org/licenses/gpl-3.0.en.html
Bill of Materials - Google Sheets
- docs.google.com/spreadsheets/d/1s2RV25Aqq35Ps_foCP7-pKksEfrfetYYAbn-AQ_H0tk/edit?usp=sharing
Cassette Futurism
- aesthetics.fandom.com/wiki/Cassette_Futurism
TI MAX3232EIPWRQ1
- ti.com/lit/ds/symlink/max3232e-q1.pdf?ts=1736232244138
FD CAN bus
- en.wikipedia.org/wiki/CAN_FD
ST M24C64-RMN6P - 64 KiB EEPROM
- st.com/resource/en/datasheet/m24c64-f.pdf
I2C (Inter-Integrated Circuit) Bus
- en.wikipedia.org/wiki/I2C
SPI (Serial Peripheral Interface)
- en.wikipedia.org/wiki/Serial_Peripheral_Interface
GPIO (General Pupose Input/Output)
- en.wikipedia.org/wiki/General-purpose_input/output
Gerber File Format
- en.wikipedia.org/wiki/Gerber_format
KiCAD
- kicad.org
Ep. 98 - The Motors Spin!
- youtube.com/watch?v=ylXH46X1Iwk
ST STM32G474RET3
- st.com/en/microcontrollers-microprocessors/stm32g474re.html
MCP4726 DAC
- ww1.microchip.com/downloads/en/DeviceDoc/22272C.pdf
4N25 Opto-isolator
- vishay.com/docs/83725/4n25.pdf
JTAG
- en.wikipedia.org/wiki/JTAG
-=] Chapters
0:00 - A Small Diversion That Wasn't Small. At All.
2:00 - Feature Creep Is A Thing / Patreon Thanks
3:40 - Scotopic vision and Red LEDs
4:27 - Well, Why Don't You Just...
5:58 - Power Isolation On A PCB
7:06 - Everything Is Open Source, Hack Away!
8:16 - So Many Voltages
10:23 - Cassette Futurism and Serial Ports
11:47 - MCU, NMEA2000/CANbus, EEPROM
12:58 - The I2C and SPI Busses
14:04 - GPIO Pin Protection; When Wires Are Antennas
16:12 - Pull Up and Pull Down Resistors
17:51 - Schematics And NetNames
19:55 - High-Level Overview of Charlieplexing
23:19 - PCB Routing; The Compass Rose PCB
26:44 - Putting Part On Both Sides Of The PCB; Why?
28:36 - DRC; Design Rule Checked - The Most Annoying Good Thing
29:14 - KiCAD Has A Great Community
29:49 - 3D Renders!
31:47 - Thermal Management
32:47 - Fixing A Small Mistake; Schematic to PCB
35:13 - The Next PCB; The Main Control Unit
39:57 - Optoisolators; They're Basically Magic
40:39 - Accurate Indication With Coarse LEDs
42:10 - D-Sub Connectors. SO MANY D-SUB!
45:32 - E-Stop Logic
46:31 - My Diesel Is Gone, I Got A New Diesel
49:01 - The MCU PCB And Field Repairability
50:51 - MCU Controlled Relays And Inductive Loads
52:24 - Battery Display Board; Electric Propulsion to ABYC Standards
54:58 - Relay Unit; Super Efficient Digital Switching!
1:00:40 - What's Next?
-=] Music Attribution
Eighties Action by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0
Source: incompetech.com/music/royalty-free/index.html?isrc=USUAN1100243
Artist: incompetech.com
Touchpoint by Audionautix is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0
Artist: audionautix.com
Inner Journey by Audionautix is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0
Artist: audionautix.com
