2 layers73.9 × 29.5 mm
2 layers81.8 × 47.6 mm
Freqcount1.1
d00p44/freqcountaccurate frequency counter
- Size
- 81.8 × 47.6 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 43
- Nets
- 109
- Pads
- 273
- Tracks, vias
- 463, 73
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 28 Jun 2023
- Updated
- 8 Jul 2025
Overview
Freqcount1.1 is an open-source printed circuit board by d00p44, from the d00p44/freqcount repository on GitHub. It is a 2-layer board of 81.8 × 47.6 mm with 43 parts on 109 nets, routed with 463 tracks and 73 vias.
It is built around the WEMOS D1 MINI, 74LS390FP-E and 74AHC1G04SE, with the BAT54S and MMBT3904 among its other parts. Its parts include 12 ICs, 11 resistors, 6 diodes, 6 connectors and 3 capacitors. It belongs with the ESP8266 boards of this library.
Main components
5
WEMOS D1 MINI
A mini wifi board with 4MB flash based on ESP-8266EX, hardware version 4.0.0.LolinUncategorised
74LS390FP-E
SOP-16-20℃~+75℃ 2 20MHz、25MHz 4 4.75V~5.25V 400mW 74LS BCD Counter Programmable divide ratio SOP-16 Counters, Dividers ROHSRenesas ElectronicsCounters, Dividers
74AHC1G04SE
SOT-353-40℃~+125℃ 1 1 1.5V~3.85V 1.9V、2.9V、4.4V 1uA 2V~5.5V 500mV~1.65V 7.5ns@5V,50pF 74AHC 8mA 8mA Noise suppression function Schmitt trigger SOT-353 Inverters ROHSDiodes IncorporatedInverters
BAT54S
SOT-231 Pair Series Connection 1V@100mA 200mA 2uA@25V 30V 600mA SOT-23 Schottky Diodes ROHSMDDSchottky DiodesMMBT3904
SOT-23-55℃~+150℃ 1 NPN 100 100nA 200mA 200mW 300MHz 300mV 40V 6V NPN SOT-23 Bipolar (BJT) ROHSJiangsu Changjing Electronics Technology (CJ)Bipolar (BJT)
README
README.mdfreqcount
accurate frequency counter
Parts
43| Qty | Value | Footprint | References |
|---|---|---|---|
| 9 | 10k | Resistor_SMD:R_0603_1608Metric | R1, R2, R3, R4, R5, R7, R9, R10, R11 |
| 4 | 1N4448 | Diode_SMD:D_SOD-323 | D1, D2, D3, D4 |
| 4 | 74LS390 | Package_SO:SSOP-16_4.4x5.2mm_P0.65mm | U1, U2, U3, U4 |
| 3 | 100nF | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3 |
| 3 | 74AHC1G04 | Package_TO_SOT_SMD:SOT-23-5 | U5, U8, U12 |
| 2 | 74LV8154 | Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm | U6, U9 |
| 2 | BAT54S | Package_TO_SOT_SMD:SOT-23 | D5, D7 |
| 2 | Conn_01x04_Male | Connector_JST:JST_PH_B4B-PH-K_1x04_P2.00mm_Vertical | J3, J6 |
| 2 | Conn_Coaxial | Connector_Coaxial:SMA_Amphenol_901-144_Vertical | J4, J5 |
| 2 | MCP23017_SS | Package_SO:SSOP-28_5.3x10.2mm_P0.65mm | U7, U10 |
| 1 | 1k | Resistor_SMD:R_0603_1608Metric | R8 |
| 1 | 47R | Resistor_SMD:R_0603_1608Metric | R6 |
| 1 | 500mA | Fuse:Fuseholder_TR5_Littelfuse_No560_No460 | F1 |
| 1 | Conn_01x03_Male | Connector_JST:JST_PH_B4B-PH-K_1x04_P2.00mm_Vertical | J1 |
| 1 | Conn_01x03_Male | Connector_JST:JST_PH_B3B-PH-K_1x03_P2.00mm_Vertical | J2 |
| 1 | Jumper_2_Open | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP1 |
| 1 | MMBT3904 | Package_TO_SOT_SMD:SOT-23 | Q1 |
| 1 | Quarz_Abra | Library:Quarz-Abra | QA1 |
| 1 | SW_DIP_x02 | Package_DIP:DIP-4_W8.89mm_SMDSocket_LongPads | SW1 |
| 1 | WeMos_D1_mini | Module:WEMOS_D1_mini_light | U11 |
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Questions
How big is the Freqcount1.1 PCB?
It measures 81.8 × 47.6 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Freqcount1.1 use?
43 parts, built around the WEMOS D1 MINI, 74LS390FP-E, 74AHC1G04SE and BAT54S. 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 Freqcount1.1 KiCad files?
From the d00p44/freqcount repository on GitHub, at the commit this page was made from: the board is freqcount_v2.0/freqcount1.1.kicad_pcb and its schematic freqcount_v1.1/freqcount1.1.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Freqcount1.1 design in my own project?
Its repository states no licence, so its author keeps all rights: ask d00p44 before reusing the design.