The implant schematics is shown Figure 1. The bill of materials for implant is given in [Table-1](#tabImp). The reasoning of the selected components is explained in the publication. Here, the instructions to build the implant is provided.
<details>
<summarymarkdown="span">Getting started with the breakout board</summary>
<summarymarkdown="span"><i>Getting started with the breakout board</i></summary>
The BLE system on chip (SoC) is selected for its high data rate. BLEv5.x stronger physical layer (PHY) compared to BLEv4.x. Its theoretical datarate can go up to 2Mbps. The used SoC is [cc2652RB][aa] from Texas Instruments (TI). It does not require an external cyrstal oscillator, which is nice to consider when there is size constraint. Nevertheless, an open source hardware [breakout board][1] was used, which provides the basic external smd components for chip to operate. In addition, the number routed input/output pins is enough for the purpose of the project. First of all, please complete the initial programming of the chip described at the **firmware instructions** section. Then, we can start modifying the hardware components. If you do not start with the **firmware programming**, recovering the hardware after following hardware modifications requires a lot of time.
The BLE system on chip (SoC) is selected for its high data rate. BLEv5.x stronger physical layer (PHY) compared to BLEv4.x. Its theoretical datarate can go up to 2Mbps. The used SoC is [cc2652RB][aa] from Texas Instruments (TI). It does not require an external cyrstal oscillator, which is nice to consider when there is size constraint. Nevertheless, an open source hardware [breakout board][1] was used, which provides the basic external smd components for chip to operate. In addition, the number routed input/output pins is enough for the purpose of the project. First of all, please complete the initial programming of the chip described at the **firmware instructions** section. Then, we can start modifying the hardware components. If you do not start with the **firmware programming**, recovering the hardware after following hardware modifications requires a lot of time.
</details>
<details>
<summarymarkdown="span">Removing unnecessary serial communication hardware</summary>
<summarymarkdown="span"><i>Removing unnecessary serial communication hardware</i></summary>
We can begin with the removal of the serial connection board from breakout board to save some space. This part is marked with a scissor symbol. After this point, we can program the board via [over-the-air download (OAD)][1a]. You can find the instructions for the OAD in **firmware documentation**.</details>
We can begin with the removal of the serial connection board from breakout board to save some space. This part is marked with a scissor symbol. After this point, we can program the board via [over-the-air download (OAD)][1a]. You can find the instructions for the OAD in **firmware documentation**.
</details>
<details>
<summarymarkdown="span">Setting up DC-DC regulator for MRI setting</summary>
<summarymarkdown="span"><i>Setting up DC-DC regulator for MRI setting</i></summary>
We need to remove the smd inductor as shown in **Figure 2** because it has a ferite core, which would be saturated in MR envrionment and may damage the hardware. This inductor is needed for the DC-DC regulator of the SoC. You can continue without replacing another inductor and use the global LDO regulator. The global LDO consumes [30% more power][1b] than the default DC-DC buck converter. Instead of replacing the inductor with a air-core equvalent value, global LDO is better for the size constraints and simplicity. Please make sure that the internal DC/DC regulator is properly configured, if global LDO is used. The instructions are shown in the **firmware** section
</details>
## Bill of Materials
[Table-1](#tabImp): Bill of materials for implant
|Item No. | Name | Part name | Est. cost per Pc. [€] | Amount | Total cost [€] |
