

Pensel
A project to assist over-caffeinated electrical engineers in soldering.
- Size
- 60 × 13 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 64
- Nets
- 45
- Pads
- 198
- Tracks, vias
- 645, 53
- Pours
- 3
- Routed
- Yes
- KiCad
- KiCad 5 (file 20160815)
- Created
- 6 May 2017
- Updated
- 12 Jun 2020
Overview
Pensel is an open-source printed circuit board by TDHolmes, from the TDHolmes/Harma repository on GitHub, published under the Unlicense licence. It is a 4-layer board of 60 × 13 mm with 64 parts on 45 nets, routed with 645 tracks and 53 vias.
It is built around the LSM9DS1. Its parts include 11 resistors, 10 capacitors, 8 connectors, 4 ICs and 3 switches. It belongs with the STM32 boards of this library.
Main components
1README
README.mdHarma Project
The Harma project first came about when I was talking to my friend and (ex-)coworker Ben. We are both tinkerers and He used to work as a rework technician, so is quite good at fine pitch soldering. I however, have very shaky hands, so I shy away from anything smaller than an 0805 passive component.
That got me thinking, there are robotic assistants for surgeries, so why not for an over caffeinated tinkerer like myself?
Thus, this project was born. It consists of two major parts:
- The thing the tinkerer holds on to to control the robot
- The robotic arms holding:
- The soldering iron
- The solder
- The wire or component
The Name
Harma comes from the word Härma, which means Mimic in Swedish. A fitting name since the goal of this project is for you to control a robot that mimics your movements in a more precise and filtered way.
Sub-Components
As stated above, this project consists of two major parts: The thing the user holds to control the robot and the robotic arms itself.
Pensel
Pensel, or brush/pencil in Swedish, is the device the user interfaces with to control the robotic arms. It is this sub-component that I will first tackle to make the whole system. The design as it stands is as follows:
There will be one unified design to control the iron, solder, and/or wire/components. As such, there must be a generic control methodology built into the Pensel. The Pensel will have as follows:
- A three position toggle switch for the user to indicate what mode the Pensel is operating in (Soldering iron, solder, or wire/component).
- One push button to indicate that we are actively moving and want the robot to respond
- Another push button to do the action supported by the mode. For example:
- Feed solder
- Feed wire
- release component
The Current design
- Processor
- STM32F302K8U6
- ARM® Cortex®-M4
- 72MHz
- CAN, I²C, IrDA, LIN, SPI, UART/USART, USB
- DMA, I²S, POR, PWM, WDT
- Hardware FPU
- Sensors
- Combined Accelerometer and Magnetometer (LSM303DLHC) to detect orientation & movement
- A button to trigger "active" mode
- An auxiliary button to generate an action
- A three position switch to indicate the active mode
- A thumbwheel potentiometer to control sensitivity
Robotic Arms (Working title)
This section has not been thought through yet. I am currently only focusing on the Pensel sub-component.
Parts
64| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | via-1.0mm | TylerCustom:via-1.0mm | , , , , , , , , , , , , , , , |
| 9 | 4K7 | Resistors_SMD:R_0402 | R1, R2, R3, R4, R8, R9, R10, R11, R12 |
| 8 | 0.1 uF | Capacitors_SMD:C_0402 | C_NOSTUFF1, C_NOSTUFF2, C2, C4, C6, C7, C12, C13 |
| 5 | 1 uF | Capacitors_SMD:C_0402 | C8, C9, C10, C11, C14 |
| 2 | 330R | Resistors_SMD:R_0402 | R5, R6 |
| 2 | 8 pF | Capacitors_SMD:C_0402 | C15, C16 |
| 2 | Fiducial | Fiducials:Fiducial_1mm_Dia_2.54mm_Outer_CopperBottom | J2, J5 |
| 2 | Fiducial | Fiducials:Fiducial_1mm_Dia_2.54mm_Outer_CopperTop | J6, J7 |
| 1 | 10 nF | Capacitors_SMD:C_0402 | C3 |
| 1 | 10 uF | Capacitors_SMD:C_0603 | C1 |
| 1 | 24 MHz | 416F32022CKR:OSCSC49P160X120X45-4N | Y1 |
| 1 | 4.7 uF | Capacitors_SMD:C_0402 | C5 |
| 1 | AUX | Buttons_Switches_SMD:SW_SPST_B3SL-1002P | SW3 |
| 1 | COMS | Pin_Headers:Pin_Header_Straight_1x06_Pitch2.00mm | J4 |
| 1 | JTAG | Pin_Headers:Pin_Header_Straight_2x05_Pitch1.27mm | J3 |
| 1 | Jumper | Resistors_SMD:R_0402 | JP1 |
| 1 | LED0 | LEDs:LED_0402 | D2 |
| 1 | LED1 | LEDs:LED_0402 | D3 |
| 1 | LSM9DS1 | LSM9DS1:PQFN24P43_350X300X102L35X23N | U2 |
| 1 | MAIN | Buttons_Switches_SMD:SW_SPST_B3SL-1002P | SW2 |
| 1 | NCP114 | TO_SOT_Packages_SMD:SC-70-5 | U3 |
| 1 | NCP508 | TO_SOT_Packages_SMD:SC-70-5 | U4 |
| 1 | STM32F302x6/8 | Housings_DFN_QFN:QFN-32-1EP_5x5mm_Pitch0.5mm | U1 |
| 1 | TACT_4.2MM | MF_Switches:MF_Switches-TACT4.2MM | SW1 |
| 1 | TEST_1P | Measurement_Points:Measurement_Point_Round-SMD-Pad_Small | J1 |
| 1 | USB_PROC | TylerCustom:2013499-1 | P1 |
Questions
How big is the Pensel PCB?
It measures 60 × 13 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Pensel use?
64 parts, built around the LSM9DS1. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Pensel KiCad files?
From the TDHolmes/Harma repository on GitHub, at the commit this page was made from: the board is Pensel/board/Pensel.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Pensel design in my own project?
Its repository publishes it under the Unlicense licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
Similar boards
- 2 layers37.8 × 21.5 mm

- 4 layers160 × 73.2 mm

MainPCB
doppelgrau/esp32-f9p-io-board
An IO-PCB (two motor-driver/H-bridge, CAN, RS232, ADS1115, relay, ethernet, ardusimple f9p compatible connector) with an ESP32 for 12V power, three 15V tolerant analog inputs, three 5V tolerant inputs.
162 parts39 - 2 layers43 × 43 mm

- 4 layers128 × 184 mm

Cosmicpi 1.7
CosmicPi/CosmicPiV1.7PCB
PCB for Version 1.7 of the Cosmic Pi Hardware. Incremental changes from V1.6. This design is licensed under the CERN OHL V1.2
219 parts14 - 6 layers44 × 118 mm

3210retro test
DasBasti/NokiaRetroFit
Retrofitting a Nokia 3210 with modern Processor
195 parts9Apache-2.0 - 4 layers35 × 44.6 mm

- 2 layers47.2 × 35 mm

- 4 layers57 × 74.3 mm

CM4
ybabs/H745FCS
Quadcopter Flight Controller based on the dual core STM32H745 Microcontroller
101 parts6