2 layers333.4 × 149.9 mm
4 layers45 × 65 mm
PICclock
kellertk/PICclockIt's a variable clock for homebrew computers. Driven by a PIC microcontroller.
- Size
- 45 × 65 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 26
- Nets
- 32
- Pads
- 102
- Tracks, vias
- 183, 44
- Pours
- 3
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 23 Jan 2026
- Updated
- 9 Feb 2026
Overview
PICclock is an open-source printed circuit board by kellertk, from the kellertk/PICclock repository on GitHub. It is a 4-layer board of 45 × 65 mm with 26 parts on 32 nets, routed with 183 tracks and 44 vias.
It is built around the EL7232CNZ and 74HCT00D. Its parts include 8 capacitors, 4 resistors, 3 ICs, 3 connectors and 3 switches. It belongs with the lEDs and displays boards and the PIC boards of this library.
Main components
2
EL7232CNZ
PDIP-8-40℃~+85℃ 4.5V~16V Driver Low-power mode PDIP-8 Ethernet Transceivers ROHSELANTECEthernet Transceivers
74HCT00D
SO-14-40℃~+125℃ 100mV、400mV 12ns@4.5V,50pF 2 2V 3.7V、4.4V 4 4.5V~5.5V 40uA 4mA 4mA 74HCT Series 800mV NAND Gate Overvoltage-tolerant input TTL Compatible CMOS SO-14 Logic Gates ROHSNexperiaLogic Gates
README
README.mdPICclock
Variable-frequency clock generator using PIC16F18344 hardware NCO.
See src/README.md and hardware/README.md for details.
Features
- 1 Hz to 1 MHz output with 50% duty cycle
- Hardware NCO for 12+ Hz (zero CPU overhead)
- Software timing for 1-11 Hz
- Logarithmic frequency sweep via potentiometer
- Step mode for single pulses
Building
-
Run the configure script:
- Windows:
.\configure.ps1 - Linux/macOS:
./configure
- Windows:
-
Build:
make -
Flash:
make flash
Requirements
- Microchip XC8 compiler
- MPLAB X IDE (for IPE and DFP)
- PICkit 5 (or compatible programmer)
- PIC16F1xxxx_DFP device family pack
License
This project is intentionally available under a restrictive license: CC BY-NC-SA. Commercial use of this work is not permitted without prior agreement. Please contact me if you need alternate licensing terms. See LICENSE.txt for details.
Parts
26| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | 100nF | Capacitor_THT:C_Disc_D6.0mm_W2.5mm_P5.00mm | C2, C6, C8 |
| 3 | 10nF | Capacitor_THT:C_Disc_D6.0mm_W2.5mm_P5.00mm | C1, C5, C7 |
| 2 | 22pF | Capacitor_THT:C_Disc_D6.0mm_W2.5mm_P5.00mm | C3, C4 |
| 2 | 470R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2, R4 |
| 2 | LED | LED_THT:LED_D3.0mm_FlatTop | D1, D2 |
| 1 | 10K | Potentiometer_THT:Potentiometer_Bourns_3339P_Vertical | RV1 |
| 1 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1 |
| 1 | 25MHz | Crystal:Crystal_HC49-U_Vertical | Y1 |
| 1 | 47R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3 |
| 1 | 74HCT00 | Package_DIP:DIP-14_W7.62mm_Socket_LongPads | U2 |
| 1 | CLK_OUT | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J2 |
| 1 | CXO_DIP14 | Oscillator:Oscillator_DIP-14_LargePads | Y2 |
| 1 | EL7232CNZ | Package_DIP:DIP-8_W7.62mm_Socket_LongPads | U3 |
| 1 | HS/[VAR/STEP] | Button_Switch_THT:SW_Slide-03_Wuerth-WS-SLTV_10x2.5x6.4_P2.54mm | SW2 |
| 1 | ICSP | Connector_PinSocket_2.54mm:PinSocket_1x06_P2.54mm_Vertical | J1 |
| 1 | PIC16F18344-P | Package_DIP:DIP-20_W7.62mm_Socket_LongPads | U1 |
| 1 | PWR_IN | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J3 |
| 1 | STEP | Button_Switch_Keyboard:SW_Cherry_MX_1.00u_PCB | SW3 |
| 1 | VAR/STEP | Button_Switch_THT:SW_Slide-03_Wuerth-WS-SLTV_10x2.5x6.4_P2.54mm | SW1 |
Questions
How big is the PICclock PCB?
It measures 45 × 65 mm and has 4 copper layers, 1.6 mm thick.
What parts does the PICclock use?
26 parts, built around the EL7232CNZ and 74HCT00D. 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 PICclock KiCad files?
From the kellertk/PICclock repository on GitHub, at the commit this page was made from: the board is hardware/kicad/PICclock.kicad_pcb and its schematic hardware/kicad/PICclock.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the PICclock design in my own project?
Its repository states no licence, so its author keeps all rights: ask kellertk before reusing the design.
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