> For the complete documentation index, see [llms.txt](https://hrftank.gitbook.io/hrftank/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hrftank.gitbook.io/hrftank/iii-build-manual-electronics/electronics-overview.md).

# Electronics overview

Welcome to the (cable) jungle!

<figure><img src="https://673609632-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhmKl11OGPwbKiNEUvA5L%2Fuploads%2FHZN8fs28Ot7DF2YTrWIC%2Felectronics%20overview2.png?alt=media&amp;token=5127661e-8be2-40be-a1e6-245a8a8ed077" alt=""><figcaption><p>Red - main power lines<br>Orange - receiver signal line<br>Yellow - FPV signal<br>Green - lighting<br>Blue - water cooling<br>Black - miscellaneous: signal lines, fan power, etc.</p></figcaption></figure>

In this part of the build guide, you **don't have to strictly follow the instructions**. You can choose which components to include in your version of the tank and which ones to leave out – it all depends on how you plan to use the vehicle, how much free time you have, and what your budget is. **Treat the following subsections purely as suggestions** and a description of how I installed various (more or less) tested components in my own version of the Tank.

**In my configuration, the HRF Tank's electronics consist of the following:** (my components are in *italics*)

* Tank power and control system:
  * Battery -  3S or 4S Lithium-polymer \
    *4S 8000mAh Bashing Li-po*
  * Fixed-wing flight controller with iNav - integrates signals from the RC receiver and transmits power from the battery to the ESCs \
    *Matek H743-WING V2 (slightly overkill, but...)*
  * ESC (x2) - bidirectional, 70A max, water-cooling capable, for brushless motors \
    *Flycolor 70A ESC*
  * Brushless DC motors (x2) – 3660-size , waterproof, low-KV optimized for higher torque\
    *Surpass Hobby 3660 1750KV*
  * RC receiver - using ELRS protocol\
    *Happy Model EP1*
  * Custom *Power Distribution Board* (PDB) - 9A capable 12 V  step-down/step-up voltage regulator board, that power to the Main PCB
* Analog FPV system:
  * Front FPV camera - analog, mini size\
    *Foxeer Predator v4*
  * Rear FPV camera - nano size\
    *Caddx Ant*
  * FPV Video transmitter with antenna -&#x20;

    *AKK FX2 Ultimate + RHCP stubby antenna*
  * 3-channel FPV Video switcher - not necessary if you want to use one FPV camera or your FC has two camera inputs
* *HRF Tank Main PCB* - consists of an Arduino Nano ESP32 development board and several MOSFETs. It receives signals from temperature sensors, manages the water-cooling system, and also controls the lighting. Thanks to the use of the ESP32, it enables wireless data transmission, such as real-time power system temperature readings
* Lighting
  * 3W LED (x2) - Cool white 6500K
  * Red + white THT LED (2 sets)
* Temperature control and cooling system:
  * DS18B20 digital temperature sensor, THT package (x4)
  * Water cooling temperature sensor
  * 370 liquid cooling pump
  * Radiator fan (x2) - 12V, 80x80x20
* Miscellaneous
  * VTx cooling radial fan - 4010, 12V
  * PDB cooling fan - 5010, 12V

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A more detailed BOM is provided in each system subsection.
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