Differences

This shows you the differences between two versions of the page.

--- power_switch [2015/11/15 20:57] – [Integrate it into a housing] breaker27
+++ power_switch [2025/07/12 20:26] (current) – [Partlist (in buildup order)] breaker27
@@ Line 3: / Line 3: @@
 ===== Needed Parts and PCB =====
-You need a **PCB**. You may use the layout from [[https://github.com/breaker27/smarthomatic/tree/develop/hardware/power_switch_1|Github]] and etch it yourself or [[https://www.smarthomatic.org/shop/|order]] the PCB or a complete kit.
+You need a **PCB**. You may use the layout from [[https://github.com/breaker27/smarthomatic/tree/develop/hardware/power_switch_1|Github]] and etch it yourself or let a company produce one for you using the layout.
 ==== Partlist (in buildup order) ====
 ^  Amount  ^               Part                      ^  Placing   ^             Picture                    ^
-|    1     | PCB Power Switch 1                      |            |  {{ parts:pcb_power_switch.jpg }}      |
+|    1     | PCB Power Switch 1                      |            |  {{ parts:pcb_power_switch.jpg }}  |
-|    2     | Diode 1N4148                            | D1, D2     |  {{ parts:diode_1n4148.jpg }}          |
+|    2     | Diode 1N4148                            | D1, D2     |  {{ parts:diode_1n4148.jpg }}      |
-|    2     | Resistor 560R green-blue-brown          | R1, R2     |  {{ parts:resistor_560r.jpg }}         |
+|    2     | Resistor 560R green-blue-brown          | R1, R2, R6 |  {{ parts:resistor_560r.jpg }}     |
-|    1     | Resistor 1M brown-black-green           | R3         |  {{ parts:resistor_1m.jpg }}           |
+|    1     | Resistor 1M brown-black-green           | R3         |  {{ parts:resistor_1m.jpg }}       |
-|    1     | IC holder                               | IC1        |  {{ parts:ic_holder.jpg }}             |
+|    2     | Resistor 22k red-red-orange (optional for battery voltage measurement)       | R4         |  {{ parts:resistor_22k.jpg }}         |
-|    1     | Voltage regulator LP2950Z               | IC3        |  {{ parts:ic_lp2950z.jpg }}            |
+|    2     | Resistor 39k orange-white-orange (optional for battery voltage measurement)  | R5         |  {{ parts:resistor_39k.jpg }}         |
-|    1     | Transistor BC547C                       | T1         |  {{ parts:transistor_bc547c.jpg }}     |
+|    1     | IC holder                               | IC1        |  {{ parts:ic_holder.jpg }}         |
-|    1     | LED 2mA                                 | LED1       |  {{ parts:led_yellow.jpg }}            |
+|    1     | Voltage regulator LP2950Z               | IC3        |  {{ parts:ic_lp2950z.jpg }}        |
+|    1     | Transistor BC547C                       | T1         |  {{ parts:transistor_bc547c.jpg }} |
+|    1     | Transistor BC327                        | Q1         |  {{ parts:transistor_bc327.jpg }} |
+|    1     | LED 2mA                                 | LED1       |  {{ parts:led_yellow.jpg }}        |
 |    1     | Connector AVR ISP 6pin angled           | JP1        |  {{ parts:connector_isp_angled.jpg }}  |
 |    1     | Connector Switched Output 3pin          | X1         |  {{ parts:connector_clamp_3pin.jpg }}  |
-|    1     | Connector 1 pin header (for serial TX debugging)  | JP5        |  {{ parts:connector_pinheader.jpg }}   |
+|    1     | Connector 1 pin header (for serial TX debugging)  | JP5 | {{ parts:connector_pinheader.jpg }} |
-|    1     | Capacitor 10µF                          | C1         |  {{ parts:capacitor_10uf.jpg }}        |
+|    1     | Capacitor 100µF                         | C1, C2     |  {{ parts:capacitor_10uf.jpg }}    |
-|    1     | Capacitor 1µF                           | C2         |  {{ parts:capacitor_220nf.jpg }}       |
+|    1     | Capacitor 2,2µF                         | C3         |  {{ parts:capacitor_220nf.jpg }}   |
-|    1     | IC ATMega328                            | IC1        |  {{ parts:atmega.jpg }}                |
+|    1     | IC ATMega328                            | IC1        |  {{ parts:atmega.jpg }}            |
-|    1     | Relay FTR-K1C (230V, 16A)               | K1         |  {{ parts:relay_ftr_k1c.jpg }}         |
+|    1     | Relay FTR-K1C (230V, 16A)               | K1         |  {{ parts:relay_ftr_k1c.jpg }}     |
-|    1     | Transceiver PCB RFM12B                  | IC2        |  {{ parts:ic_rfm12b.jpg }}             |
+|    1     | Transceiver PCB RFM12B                  | IC2        |  {{ parts:ic_rfm12b.jpg }}         |
-|    1     | Antenna (82,2mm wire)                   |            |  {{ parts:antenna.jpg }}               |
+|    1     | Antenna (82,2mm wire)                   |            |  {{ parts:antenna.jpg }}           |
 maybe extra pins, at your opinion.
@@ Line 41: / Line 44: @@
   * **RFM12B:** You should also check the voltages first before soldering the module. At the place for the radio module the pad beside the antenna and at the opposite side the third pad should read about 3.3 V. For soldering, read [[rfm12b_soldering|the RFM12B mounting instructions]].
   * **Relais:** If you want to switch high currents, especially at high voltages, it is recommended to solder the wires directly to the relais pins on the bottom of the PCB.
+  * **R4+R5:** The values of the resistors need to be matching your battery voltage so that the voltage measured from the R4+R5 voltage divider is not higher than 3.3V (the maximum voltage the ATmega can measure with its 3.3V power supply). Both values can also be higher to reduce battery consumption (calculate the current using Ohm's law). The values should not be too high, considering the input impedance of the ATMega ADC pins of around 1 MOhm.
 {{https://raw.github.com/breaker27/smarthomatic/develop/hardware/power_switch_1/placing.png?500}}
@@ Line 56: / Line 60: @@
 ===== Integrate it into a housing =====
-describe it...
+The PCB can be integrated into a housing to act as a wireless power plug or in other housings as needed to switch other devices.
-===== Modification of RFM12 power pin (PCB < V1.1) =====
+===== Modification of RFM12 power pin (PCB V1.0) =====
 In PCBs >= V1.1, the RFM12 power pin is connected to an ATMega I/O pin to make it possible to restart the transceiver if communication fails.
@@ Line 64: / Line 68: @@
 If you want to modify your old PCB version to have this feature as well, cut two traces carefully (marked red in the picture) and connect two pins of the RFM transceiver to the ATMega (marked green in the picture).
+Make sure you don't create a short circuit and cut the traces correctly. Use a multimeter to check this.
-{{:powerswitch_v1_mod.jpg?100|}}
+{{:powerswitch_v1_mod.jpg?500|}}
+===== Modification of RFM12 power pin (PCB V1.1) =====
+The PCB V1.1 has a fault in it's layout (not in the schematic though). Sadly, the ATMega PC3 pin is not only connected to power the RFM12, but is as well connected to the 3.3V line. Therefore the RFM12 has always power and the restart in case reception is not working anymore is not working like with the modified PCB 1.0 (see above).
+To fix this, a copper trace needs to be cut at the point shown on the picture. If you do this modification, it's recommended to check with a multimeter that the RFM12 pin is not connected to 3.3V anymore, but to the PC3 pin of the ATMega.
+{{:powerswitch_v11_short_circuit_mod.jpg?500|}}
+===== Add battery measurement support (PCB V1.1) =====
+If you want to add the possibility to measure the battery voltage / percentage to PCB V1.1, which is otherwise a new feature of PCB V1.2, you can solder the resistors directly to the power pins at the bottom side of the PCB and connect the voltage divider to PC5.
+{{:powerswitch_v11_battery_mod_1.jpg?500|}}
+{{:powerswitch_v11_battery_mod_2.jpg?500|}}