Update README.md

README.md

@@ -19,14 +19,14 @@ pumps. Controller can be easily used for newly designed heat pumps (HPs), includ
 <br><br>
 
 ## Refrigeration schemes supported
-- Heat Pump (HP) with Electronic Expansion Valve (EEV)
+- Heat Pump (HP) with Electronic Expansion Valve (EEV),
-- HP with capillary tube,
+- HP with capillary tube or TXV,
-- EEV only controller
+- EEV only controller.
 <br><br>
 
 ## Installations supported
-- Indoor: a house or technical building with a more or less stable temperature
+- Indoor: a house or technical building with a more or less stable temperature,
-- Outdoor: harsh climatic conditions taken into account and tested down to minus 32°C
+- Outdoor: harsh climatic conditions taken into account and tested down to minus 32°C.
 <br><br>
 
 ## Changelog and history
@@ -39,16 +39,16 @@ pumps. Controller can be easily used for newly designed heat pumps (HPs), includ
 ## Get your own copy and PCB assembly
 - download the PCB gerber file, *Gerber.zip*
 - find in Google, [where to order a printed circuit board](https://www.google.com/search?q=order+pcb+gerber) (keywords: order pcb gerber), place an order,
-- order electronic components, see BOM (Bill Of Materials) list, *PCB_BOM.html*
+- order electronic components, see BOM (Bill Of Materials) list, *PCB_BOM.html* ,
-- solder electronic components {- assembly instructions here-}
+- solder electronic components. {- assembly instructions here-}
 
 ## Firmware upload
-The process is the same as for others Arduinos 
+The process is the same as for others Arduinos:
-- connect USB-> UART converter 
+- connect USB-> UART converter,
-- start Arduino IDE
+- start Arduino IDE,
-- open the firmware file
+- open the firmware file,
-- select board and MCU in the Tools menu (hint: we are using "mini" board with 328p MCU)
+- select board and MCU in the Tools menu (hint: we are using "mini" board with 328p MCU),
-- press the "Upload" button in the interface and "Reset" on the Arduino
+- press the "Upload" button in the interface and "Reset" on the Arduino.
 
 For arduinos with old bootloader you need to update it. (Tools-> Burn Bootloader).<br>
 For successful compilation, you must have "SoftwareSerial", "OneWire" and "DallasTemperature" installed (see Tools -> Manage Libraries).<br>
@@ -57,15 +57,15 @@ As a first try it's enough to simply upload firmware without any tunings. Think
 ## Self-tests
 QA tests are available to test the assembled board.<br>
 Self-test helps you check relays, indicators, speaker and temperature sensors.<br>
-To run a self-tests
+To run a self-tests:
-- uncomment this 3 defines in source code header
+- uncomment this 3 defines in source code header,
 ```c
 //#define SELFTEST_RELAYS_LEDS_SPEAKER    //speaker and relays QA test, uncomment to enable
 //#define SELFTEST_EEV                    //EEV QA test, uncomment to enable
 //#define SELFTEST_T_SENSORS              //temperature sensors QA test, uncomment to enable
 ```
-- upload firmware
+- upload firmware,
-- connect 12V power supply<br>
+- connect 12V power supply.<br>
 
 Video {- demostration "How self-tests works":-}
 To check EEV, you can use a stepper motor as shown in the video. If you are testing a real EEV, it should be closed after the first "beep" and partially opened after the second "beep".<br>
@@ -76,23 +76,23 @@ To check temperature sensors connectors prepare one array of sensors. Connect it
 ## Wiring and installation
 Wiring is very simple despite the many connections: <br>
 Phases (1st wire in electrical cables):
-- connect the "power inlet" wire to one of the "phase" connectors
+- connect the "power inlet" wire to one of the "phase" connectors,
-- and connect the second "phase" connector to the AC input of the 12V power supply
+- and connect the second "phase" connector to the AC input of the 12V power supply,
-- connect the "Compressor" relay output to the Compressor input
+- connect the "Compressor" relay output to the Compressor input,
-- connect the relay output "Hot CP" to the input of the Hot Circulation Pump (pump of the water floor heating system or the fan input of the indoor unit if you are using an air system)
+- connect the relay output "Hot CP" to the input of the Hot Circulation Pump (pump of the water floor heating system or the fan input of the indoor unit if you are using an air system),
-- connect the relay output "Cold CP" to the input of the Cold Circulation Pump (ground loop pump for geothermal systems or the inlet of the outdoor unit air fan if you are using an air system)
+- connect the relay output "Cold CP" to the input of the Cold Circulation Pump (ground loop pump for geothermal systems or the inlet of the outdoor unit air fan if you are using an air system),
 - when using a compressor heater: connect the "Crankcase heater" output to the heater cable input (highly recommended for outdoor installation and year-round use)
-Neutral (2nd cable in electrical cables):
+Neutral (2nd cable in electrical cables),
-- connect all the second wires to the "neutral" connectors on the board
+- connect all the second wires to the "neutral" connectors on the board.
 
 {-Photo of HV connections-}<br>
 
 Crimp and connect low-voltage connectors:
-- SCT013 sensor (the only low-voltage device in the circuit with interchangeable contacts), connect and install on the phase inlet wire
+- SCT013 sensor (the only low-voltage device in the circuit with interchangeable contacts), connect and install on the phase inlet wire,
-- RS485 through a wire of the desired length to the remote control display (if used, another control method is a local computer with a USB-UART converter, you may like it for the first time). Note that A is connected to A in the display, B to B and GND to GND
+- RS485 through a wire of the desired length to the remote control display (if used, another control method is a local computer with a USB-UART converter, you may like it for the first time). Note that A is connected to A in the display, B to B and GND to GND,
-- you can power the display from a 12V controller, the board has 12V and GND secondary pins
+- you can power the display from a 12V controller, the board has 12V and GND secondary pins,
-- EEV to EEV connector
+- EEV to EEV connector,
-- T sensors to T sensors connectors
+- T sensors to T sensors connectors,
 - connect the outputs of the pressure sensors: 1st wires together to the right pin, 2nd cold side wire to the left terminal, 2nd hot side wire to the middle terminal; use the dummy when pressure sensors are not in use.
 
 You may prefer to solder the wires over using connectors. But in this case, it will be more difficult to disassemble the system if you want to change something. The choice is yours.<br>
@@ -124,16 +124,16 @@ link
 This is not a hard part, but if you don't have experience it will take time. <br>
 You have performed a pressure test and vacuumated your system. It's time to charge.<br>
 Let's say you don't know how to calculate the amount of refrigerant in a newly built system:
-- charge a small amount (for example 300 g) of refrigerant
+- charge a small amount (for example 300 g) of refrigerant,
-- start the heat pump
+- start the heat pump,
-- at this moment the suction temperature (according to the suction pressure on the pressure gauge) will be about -20 ...- 40 ° C
+- at this moment the suction temperature (according to the suction pressure on the pressure gauge) will be about -20 ...- 40 ° C,
 - for single-component refrigerants: slightly open the valve of the HVAC gauge manifold to start adding refrigerant through the gas phase on the cold side,
-- for multi-component refrigerants: turn over the refrigerant cylinder, VERY SLIGHTLY open the HVAC manifold valve to start adding a VERY LITTLE amount of refrigerant through the liquid phase
+- for multi-component refrigerants: turn over the refrigerant cylinder, VERY SLIGHTLY open the HVAC manifold valve to start adding a VERY LITTLE amount of refrigerant through the liquid phase,
 - carry out charging until the suction temperature (according to the suction pressure on the manometer) is ~ 10 ... 15 ° C lower than the temperature of the heat source (example: the temperature at the inlet of the mixture of water and antifreeze from the closed ground loop is + 8 ° C, so the suction temperature should be -2 ..- 7), then close the manifold valve,
-- at every step check the discharge pressure: it should not be too high compared to the temperature from the discharge sensor (Tbc) of the hot side.
+- at every step check the discharge pressure: it should not be too high compared to the temperature from the discharge sensor (Tbc) of the hot side,
-- wait for the system to heat the target to a more or less stable temperature, add refrigerant while temperature increases (and suction decreases)
+- wait for the system to heat the target to a more or less stable temperature, add refrigerant while temperature increases (and suction decreases),
-- stop if you are sure that the heating process is now proceeding very slowly
+- stop if you are sure that the heating process is now proceeding very slowly,
-- carry out the final charge when the system is stable and the heat pump stops normally (setpoint is reached), this may take 12 hours or more, and now the target difference between the suction pressure temperature and the temperature from the T sensor should be 3 ... 6 ° C,
+- carry out the final charge when the system is stable and the heat pump stops normally (setpoint is reached), this may take 12 hours or more, and now the target difference between the suction pressure temperature and the temperature from the T sensor should be 3 ... 6 ° C.
 
 This algo is good and safe both the first time and as a starting point. As you gain experience, you will get yours much easier and faster.<br>
 Also use "manual EEV mode" during charging process.<br>