## 7 Migrating Existing OSH Designs to SensoTube Architecture
### Decoupling from the Programming and Debugging Function  
The biggest portion of the energy wastage demonstrated in the beginning of this section, is due to the programming and debugging circuitry. According to the SensoTube architecture, this circuitry should be decoupled from the WSAN system through its implementation in the form of a PDL functional shield. As a proof of the proposed concept, we take the case of Arduino Uno Rev. 3 as a use case. We took the schematic file of this specific board from the original webpage of Arduino and we broken \(\upsilon\)t down into three parts: the MCU circuitry (Figure 38); the programming and debugging circuitry (Figure 39); and, the power management circuitry (Figure 40). The programming and debugging of the MCU of the Arduino Uno Rev. 3 is performed through the UART's TXD and RXD signal pins (see Figures 38 and 39). The SensoTube facilitates the routing of these two signals through the pins of the S-BEC1. Thus, it is very easy to decouple the circuitries of the MCU and the programming and debugging which can be realized in form of separated functional shields. On the other hand, as it can be seen in Figure 40, the circuitry of power management is devoted just to regulate the external supply voltage and serve power to the MCU circuitry. According to the SensoTube concept, the power management circuitry can be also decoupled from the main-board and to be accommodated onto a PML functional shield. In this way, there is also the opportunity to make such design options so as to satisfy the forecasted energy supply of all of the expansion shields of the system. Among the most significant advantages of the proposed functions decoupling there are the dramatic reduction of energy consumption at the functional MCU-based shield and the reusability of expansion shields due to their austere implementation. At the same time there are also advantages in terms of the cost of the decoupled implementations. Below we show Tables 5-7 with the part-numbers, descriptions and prices of the components used in the aforementioned three Arduino Uno Rev. 3 circuits. The prices are based on unit costs, and they taken from the Mouser Electronics' webpage (www.mouser.com). Figure 37: A realistic representation of the fabricated new DCL shield. Figure 38: The MCU circuitry of the Arduino Uno Rev. 3. Figure 39: The programming and debugging circuitry of the Arduino Uno Rev. 3. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**\#** & **Component** & **Description** & **Qty** & **Part Number** & **Manufacturer** & **Cost (euros)** \\ \hline
1 & C7 & Capacitor & 1 & CC0603 KKX7R9 BB104 & Yagoe & 0.091 \\
2 & C5 & Capacitor & 1 & CC0603 KKX7R9 BB104 & Yagoe & 0.091 \\
3 & C8 & Capacitor & 1 & GRM188R6J0105 KA01D & Murata & 0.091 \\
4 & C11 & Capacitor & 1 & 500R14N220 JV4T & Johanson & 0.091 \\
5 & C9 & Capacitor & 1 & 500R14N220 JV4T & Johanson & 0.091 \\
6 & ICSPI & Connector & 1 & 67996-406 HLF & FCI & 0.244 \\
7 & ICSP & Connector & 1 & 67996-406 HLF & FCI & 0.244 \\
8 & X2 & Connector & 1 & USB-B11 GW6 & On Shore & 0.58 \\
9 & XT1 & Crystal & 1 & CSTC16M0V53-R0 & Murata & 0.416 \\
10 & D3 & Diode & 1 & CD1206-S01575 & Bourns & 0.142 \\
11 & L1 & Ferrite & 1 & BLM21 PG221 SN1D & Murata & 0.1 \\
12 & U3 & IC & 1 & ATMEGA16U2-MUR & Atmel & 3.93 \\
13 & RX & LED & 1 & APT2012 YC & Kingbright & 0.119 \\
14 & TX & LED & 1 & APT2012 YC & Kingbright & 0.119 \\
15 & F1 & PTC & 1 & MF-MSM6050-2 & Bourns & 0.208 \\
16 & R1 & Resistor & 1 & ERJ-3 GEY105V & Panasonic & 0.091 \\
17 & R2 & Resistor & 1 & ERJ-3 GEY105V & Panasonic & 0.091 \\
18 & RN4 & Resistor & 1 & CAY16-102J4 LF & Bourns & 0.095 \\
19 & Z1 & Variator & 1 & CG0603 MLC-05E & Bourns & 0.18 \\
20 & Z2 & Variator & 1 & CG0603 MLC-05E & Bourns & 0.18 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: The parts list of the programming and debugging circuitry of Arduino Uno Rev. 3. Figure 40: The power management circuitry of Arduino Uno Rev. 3.