# Water Level Indicator ## Description Daddy's first PCB. Measures the water level of a potted plant, displays the level using LEDs. ## Project Details - **Owner:** brooks - **Created:** 3/14/2022 - **Last Updated:** 3/20/2026 - **Visibility:** Public - **System Architecture:** flowchart TD Bat["5V Battery"] --> V5["5V Rail"] V5 --> U_LM324["LM324 Comparators"] V5 --> U_EV1527["EV1527 Encoder"] V5 --> U_SYN115["SYN115 433MHz TX"] Probes["Probe Header C L1 L2 L3 L4"] --> U_LM324 U_LM324 --> LEDs["4 LEDs with 2.2k resistors"] U_LM324 --> U_EV1527 U_EV1527 -->|DATA| U_SYN115 U_SYN115 --> Ant["Antenna Pad 17cm Wire"] GND["GND Copper Pour"] --- U_LM324 GND --- U_EV1527 GND --- U_SYN115 GND --- LEDs - **test:** test - **Stars:** 3 - **Forks:** 5 - **Copies:** 4 ## Key Components ### CN1 — [WAFER-XH2.54-5PLB](https://www.flux.ai/lcsc/wafer-xh2p54-5plb~t75s.md) - Package: 2.54mm 1x5 SMD - Manufacturer Name: XUNPU(讯普) - JLCPCB Part Class: Extended Part - Role Details: Water probe header: C, L1, L2, L3, L4 - LCSC Part Number: C3029470 - Manufacturer Part Number: WAFER-XH2.54-5PLB - Package or Case Code: CONN-SMD_5P-P2.50_XUNPU_WAFER-XH2.54-5PLB - Role: Connector - Part Type: Wire To Board / Wire To Wire Connector **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] - 7 [pin 7] ### IC1 — [LM324ADR](https://www.flux.ai/adrian95/lm324adr~6ax.md) - Manufacturer Name: Texas Instruments Inc. - Datasheet URL: https://www.ti.com/lit/ds/symlink/lm224.pdf - Package: SOIC-14 - Role: Comparator - Manufacturer Part Number: LM324ADR - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: 4-level water probe comparators on 5V rail - Part Type: Operational Amplifier (OP-AMP) **Pins:** - 1IN- [pin 2] - 1IN+ [pin 3] - 1OUT [pin 1] - 2IN- [pin 6] - 2IN+ [pin 5] - 2OUT [pin 7] - 3IN- [pin 9] - 3IN+ [pin 10] - 3OUT [pin 8] - 4IN- [pin 13] - 4IN+ [pin 12] - 4OUT [pin 14] - GND [pin 11] - VCC [pin 4] ### LED1 — [LED 0805 (2012 Metric)](https://www.flux.ai/jharwinbarrozo/led-0805-2012-metric~ph.md) - Manufacturer Name: ROHM Semicon - Datasheet URL: https://datasheet.lcsc.com/lcsc/2201131330_ROHM-Semicon-SML-210VTT86_C919445.pdf - Part Type: LED - Forward Voltage: 2V - Manufacturer Part Number: SML-210VTT86 **Pins:** - A [pin 2] - K [pin 1] ### LED2 — [LED 0805 (2012 Metric)](https://www.flux.ai/jharwinbarrozo/led-0805-2012-metric~ph.md) - Datasheet URL: https://datasheet.lcsc.com/lcsc/2201131330_ROHM-Semicon-SML-210VTT86_C919445.pdf - Part Type: LED - Manufacturer Name: ROHM Semicon - Manufacturer Part Number: SML-210VTT86 - Forward Voltage: 2V **Pins:** - A [pin 2] - K [pin 1] ### LED3 — [LED 0805 (2012 Metric)](https://www.flux.ai/jharwinbarrozo/led-0805-2012-metric~ph.md) - Forward Voltage: 2V - Manufacturer Part Number: SML-210VTT86 - Manufacturer Name: ROHM Semicon - Part Type: LED - Datasheet URL: https://datasheet.lcsc.com/lcsc/2201131330_ROHM-Semicon-SML-210VTT86_C919445.pdf **Pins:** - A [pin 2] - K [pin 1] ### LED4 — [LED 0805 (2012 Metric)](https://www.flux.ai/jharwinbarrozo/led-0805-2012-metric~ph.md) - Datasheet URL: https://datasheet.lcsc.com/lcsc/2201131330_ROHM-Semicon-SML-210VTT86_C919445.pdf - Part Type: LED - Manufacturer Name: ROHM Semicon - Forward Voltage: 2V - Manufacturer Part Number: SML-210VTT86 **Pins:** - A [pin 2] - K [pin 1] ### Q1 — [BC547B](https://www.flux.ai/jharwinbarrozo/bc547b~3mr.md) - Datasheet URL: https://datasheet.lcsc.com/lcsc/2008011835_LGE-BC547B_C713613.pdf - Manufacturer Name: LGE - Part Type: Transistor - Manufacturer Part Number: BC547B **Pins:** - B - C - E ### Q2 — [BC547B](https://www.flux.ai/jharwinbarrozo/bc547b~3mr.md) - Part Type: Transistor - Datasheet URL: https://datasheet.lcsc.com/lcsc/2008011835_LGE-BC547B_C713613.pdf - Manufacturer Name: LGE - Manufacturer Part Number: BC547B **Pins:** - B - C - E ### Q3 — [BC547B](https://www.flux.ai/jharwinbarrozo/bc547b~3mr.md) - Datasheet URL: https://datasheet.lcsc.com/lcsc/2008011835_LGE-BC547B_C713613.pdf - Manufacturer Name: LGE - Part Type: Transistor - Manufacturer Part Number: BC547B **Pins:** - B - C - E ### Q4 — [BC547B](https://www.flux.ai/jharwinbarrozo/bc547b~3mr.md) - Manufacturer Part Number: BC547B - Part Type: Transistor - Manufacturer Name: LGE - Datasheet URL: https://datasheet.lcsc.com/lcsc/2008011835_LGE-BC547B_C713613.pdf **Pins:** - B - C - E ### SW1 — [PCM12SMTR](https://www.flux.ai/jharwinbarrozo/pcm12smtr~ngv.md) - Manufacturer Name: C&K - Manufacturer Part Number: PCM12SMTR - Datasheet URL: https://www.ckswitches.com/media/1424/pcm.pdf - Part Type: Switch **Pins:** - COM [pin 2] - P1 [pin 1] - P2 [pin 3] - SH1 [pin SH1] - SH2 [pin SH2] - SH3 [pin SH3] - SH4 [pin SH4] ### U1 — [EV1527](https://www.flux.ai/lcsc/ev1527~ev4u.md) - Datasheet URL: https://assets.lcsc.com/datasheet/szlcsc/Download-ISO9001-Certification.pdf - Package or Case Code: SOP-8_L4.9-W3.9-P1.27-LS6.0-BL - LCSC Part Number: C108704 - Role: Encoder - Product Info Url: https://lcsc.com/product-detail/Codec-ICs_EV1527_C108704.html - Manufacturer Name: LCX(凌承芯) - Package: SOP-8 - Role Details: Encode L25/L50/L75/L100 to OOK data - Manufacturer Part Number: EV1527 - JLCPCB Part Class: Extended Part - Part Type: Codec ICs **Pins:** - GND [pin 3] - K0 [pin 5] - K1 [pin 6] - K2 [pin 7] - K3 [pin 8] - OSC [pin 1] - TXD [pin 4] - VCC [pin 2] ### U2 — [F115](https://www.flux.ai/kicad-part-library/f115~fmm.md) - Package: SOT-23-6 - Manufacturer Name: Texas Instruments Inc. - Manufacturer Part Number: F115 - Role: RF Transmitter - Role Details: 433MHz OOK transmitter driven by EV1527 DATA - Package or Case Code: SOT-23-6 - Datasheet URL: https://datasheet.lcsc.com/lcsc/2205181716_Synoxo-F115_C3010244.pdf **Pins:** - ASK [pin 6] - PAOUT [pin 1] - VDD [pin 3] - VSS [pin 2] - XTLIN [pin 5] - XTLOUT [pin 4] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/brooks/water-level-indicator~3v](https://www.flux.ai/brooks/water-level-indicator~3v).* --- *Generated from [https://www.flux.ai/brooks/water-level-indicator~3v](https://www.flux.ai/brooks/water-level-indicator~3v)*