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gca-pi07-en [2020/01/13 12:41] (current) – created - external edit 127.0.0.1
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 +====== GCA-PI07 Transformer Sensor ======
 +[[english|{{  rocrail-logo-35.png}}]][[:rocnet:rocnetnode-en|{{ :rocnet:rocnet-hw.png}}]]
 +[[english|Content]] -> [[hardware-en|Hardware]] -> [[hardware-en#rocnet_with_raspberry_pi|GCA-RasPi]]
 +  * [[GCA1-PI01-en|GCA-PI01]] | [[:rocnet:pi01can-en|Pi01CAN]] | [[GCA_PI02-en|GCA-PI02]] | [[GCA-PI03-en|GCA-PI03]] | [[:gca-pi04-en|GCA-PI04]] | [[:gca-pi05-en|GCA-Pi05]] | [[:gca-pi06-en|GCA-Pi06]] | **[[:GCA-PI07-en|GCA-PI07]]** | [[GCA-PI08-en|GCA-PI08]] | [[:gca107-en|GCA107 Relay board]] | [[:rocnet:rocdisplay-en|RocDisplay]] | [[:rocnet:fastclock-en|Fast Clock]]
 +  * [[mgv-overview-en|The GCA modules]]
 +  * [[:rocnet:rocnetnode-en|RocNetNode]]
  
 + \\
 +|  Discontinued, due to unavailability of chip PCF8591 in DIL16. Alternative **[[:gca94-en|GCA94]]**.  |
 + \\
 +=====Introduction=====
 +Sensoring trains is a very essential part of automatic train control.\\
 +Rocrail is no exception for that.\\
 +There are various ways of keeping track of your trains.\\
 +For a longer time GCA93 current detector has been widely used because its excellent reliability.\\
 +This GCA93 is also, connected to a GCA_PI02 very useful for RocNet network.\\
 +But there is one very little disadvantage, using current detectors like GCA93 :\\
 +It looses 1.2 V of your booster power.\\
 +In practice it is hardly noticeable, specially with the modern decoders with load control.\\
 +The GCA_PI07 is made in a different way, which avoids this 1.2 V lost.\\
 +There is hardly any loss at all (approx 5 mV)\\
 +The disadvantage is a larger board, compared to GCA93.\\
 +Max four of these boards are to be connected to one Raspberry Pi.\\
 +A dip-switch on board selects the address, see table below.\\
 +The sensibility of two groups of 4 inputs can be influenced by jumpers.\\
 + \\
 +===== Features =====
 +  *  8 current inputs on each board
 +  *  Direct link to I2C in RocNet.
 +  *  Very low power loss due to use of transformers.\\
 +  *  Total 32 sensors inputs to one Raspberry Pi.\\
 +  *  The load per sensor is reported to Rocrail for **[[:sensor-gen-en#max.load|Background Color]]**.
 +
 +
 + \\
 +
 +=====The Hardware=====
 +^ Final product ^ Professional board ^
 +| {{:gca:gca_pi07_pict03.jpg?0x300}} | {{:gca:gca_pi07_pcbpict.jpg?0x300}} |
 +\\
 +===== Dip Switch settings =====
 +Maximum of 4 boards  can be used to one Raspberry Pi.\\
 +^ sensors  ^  SW 1  ^  SW2  ^
 +|  1..8  |  OFF  |  OFF  |
 +|  9..16  |  OFF  |  ON  |
 +|  17..24  |  ON  |  OFF  |
 +|  25..32  |  ON  |  ON  |
 +\\
 +
 +===== Jumper settings =====
 +Jp1 and Jp2 are to seelct a more or less sensitivity to the inputs.\\
 +There indications on board :    and 3.\\
 +Normal settings will be a jumper to pos 5.\\
 +If you need a lightly better sensitivity put the jumper on pos 3.\\
 +Jp1 is for input 1..4.\\
 +Jp2 is for input 5..8.\\
 +
 +===== Files ======
 +|{{:gca:gca_pi07_v1-2_sch.pdf}}  |
 +|{{:gca:gca_pi07_v1-2_pcb.pdf}}  |
 +|{{:gca:gca_pi07_parts.pdf}}   |
 +^ N.B. Only complete ordered kits will be supported! ^
 +
 + \\
 +===== Two ways of connecting railsections =====
 +
 +To connect railsections to GCA_PI07 there are two options.\\
 +First, the easiest way is NOT to use J2 connector, but instead loop the wire that feeds the rail section through the coil.\\
 +Usually just feeding through is sufficient, but with lower currents like waggons with 10K resistor between\\ 
 +the wheels, an extra winding will be needed.\\
 +It is never critical to use more windings.\\
 +The second option is to use connector J2.\\
 +But then you need to make 2 windings of isolated wire on each coil and connect the ends to the free solder pads\\
 +on both sides of each coil.\\
 +\\
 +===== Testing =====
 +GCA_PI07 is using a transformer to detect current.\\
 +But like every transformer, the inputs of this unit will only detect ac current.\\
 +This current can be any digital signal from central units, but also the 50 Hz of a Märklin system.\\
 +It will definitely not work with dc powered analog trains.\\
 +\\
 +
 +=====Links=====
 +  * http://www.nxp.com/documents/data_sheet/PCF8591.pdf