gca-pi08-en
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+ | ====== GCA_PI08 16 channel module with max 40V 100 mA output per channel ====== | ||
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+ | [[english|{{ | ||
+ | [[english|Content]] -> [[hardware-en|Hardware]] -> [[hardware-en# | ||
+ | * [[GCA1-PI01-en|GCA-PI01]] | [[: | ||
+ | * [[mgv-overview-en|The GCA modules]] | ||
+ | * [[: | ||
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+ | \\ | ||
+ | ^^^^By Peter Giling ^^^^ | ||
+ | [[http:// | ||
+ | \\ | ||
+ | ===== Description ===== | ||
+ | NXP created several high current output chips for I2C\\ | ||
+ | Unfortunately, | ||
+ | which makes doityourself very difficult.\\ | ||
+ | Since GCA always have been trying to make all kits really simple to build, this chip was no option this way.\\ | ||
+ | {{ : | ||
+ | A next nice feature of this chip was the built-in I2C driver, so no extra driver chip was needed, as used on other GCA_PIxx boards.\\ | ||
+ | On board, there is space for two led bars, to indicate the functioning of each ouput.\\ | ||
+ | These leds do not needed installation if you see no purpose there.\\ | ||
+ | The resistor arrays RP1 and RP2 need to be adapted to the voltage as supplied to the GCA_PI08, \\ | ||
+ | so these arrays will be mounted in sockets, making it simple to change if needed.\\ | ||
+ | Also, because of the hight Voltage of 40V max, each port can drive a large serial train of leds, using only one \\ | ||
+ | serial resistor in each chain.\\ | ||
+ | Each port can drive up to 100 mA max.\\ | ||
+ | The GCA_PI08 is part of the RocNet network, Rocrail provides of course all the setting options that are needed.\\ | ||
+ | See: __**[[: | ||
+ | The GCA_PI08 has a connection J3 \\ | ||
+ | * for power in of max 40 V dc (V+, V-) | ||
+ | * and (OE+, OE-) to connect an external switch to disable all ports.\\ | ||
+ | When not used OE+ and OE- should be bridged with a short piece of wire. | ||
+ | The connection of ports can be done in various ways.\\ | ||
+ | First of all there are two PSS 254 connectors, quit familiar in GCA kits.\\ | ||
+ | Instead of that, also a AST 021-10 connector will fit instead of PSS 254.\\ | ||
+ | Here you can simply connect wires without the need of a screw driver.\\ | ||
+ | And all outputs are also available on a 20 pin flatcable header.\\ | ||
+ | This poor quality type of connector is not really favorite inside GCA boards, but is possible anyway.\\ | ||
+ | | {{: | ||
+ | |||
+ | The standard used PSS 254/PSK254 connectors might be not the first choice of many railroaders, | ||
+ | can handle a current of at least 1,5 amp att each pin and is very rigid.\\ | ||
+ | All you need to buy is a crimping tools, available from GCA for € 20.\\ | ||
+ | Once you have that settled, you can easily make you own cables in any length with the use of 0,25 mm wire.\\ | ||
+ | The kit will be delivered with standard PSK connectors.\\ | ||
+ | In stead of PSK connectors, as delivered in the kit, also the more costly AST021 connectors can be mounted.\\ | ||
+ | Another, rather expensive option is a 10 pin detachable connector WAGO type MCS. (known for example from Intellibox rail connection)\\ | ||
+ | It will also fit instead of PSS 254 connectors.\\ | ||
+ | The position of the led bars is the next possible option. | ||
+ | In this place, a standard 2x8 pins boxheader will fit.\\ | ||
+ | The resistor array keeps its place, so you do not need any addional resistors.\\ | ||
+ | Using boxheaders here also has the nice advantage , that short circuit of any output does not do much harm.\\ | ||
+ | The outside pins of the boxheader are the + for the connected leds, the inside pins are minus.\\ | ||
+ | Please keep in mind to adapt the input power to the amount of leds that is connected to each oupput.\\ | ||
+ | For example do not use 30V power when only one led is connected to each output.\\ | ||
+ | It will result in too much heat in the resistor array!\\ | ||
+ | |||
+ | \\ | ||
+ | ==== How to find out which pcb I have? ==== | ||
+ | \\ | ||
+ | On version 1.x there is no C3 nor R3.\\ | ||
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+ | \\ | ||
+ | ===== The version 1 hardware files ===== | ||
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+ | | {{: | ||
+ | | {{: | ||
+ | | {{: | ||
+ | | {{: | ||
+ | \\ | ||
+ | ===== Version 2 ===== | ||
+ | In the first edition, it was possible to damage the PC9622 chip, when suppply was changed from 15 to 5 Volt.\\ | ||
+ | To avoid that, v2 has an extra capacitor.\\ | ||
+ | \\ | ||
+ | | {{ : | ||
+ | | {{ : | ||
+ | | {{ : | ||
+ | \\ | ||
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+ | ===== Important warnings for version 1 ! ===== | ||
+ | |||
+ | If you are using external power to be connected to J3, please be sure that this power is 100% isolated from anything else.\\ | ||
+ | It seems that some power supplies, for example, have their low voltage output connected to ground via the mains sockets.\\ | ||
+ | Where also your PC is grounded that way, serious damage on PI08 pcboard or elsewhere in the RocNet circuit might be initiated.\\ | ||
+ | Be sure of that before you connect it! \\ | ||
+ | There was no reasonable easy and payable way to make a galvanic isolation between RocNet and board PI08.\\ | ||
+ | The first goal in developing this unit was to create something that is not too expensive.\\ | ||
+ | Therefore ground level of RocNet and ground of J3 on PI08 are linked together.\\ | ||
+ | |||
+ | |||
+ | Another issue has occurred with practical test, which never have been realised here in my workshop.\\ | ||
+ | If you connect external power to J3, and later on you deside to switch back to 5V supply for the leds, \\ | ||
+ | it appears that capacitor C2 is fully charged.\\ | ||
+ | Since there is no more drain for that capacitor, it will put the full charge into the 5V circuit, | ||
+ | Version 2 has a protection for that.\\ | ||
+ | An option for version 1 is to fix a resistor of +/- 10 KOhm between the + and - of the large Elco.\\ | ||
+ | Just fit it at the bottom side of the pcb.\\ | ||
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+ | \\ | ||
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+ | ===== Jumper JP1 en power supply ===== | ||
+ | The on-board chip is connected to 5 V of the RocNet bus.\\ | ||
+ | But the common anode of all leds to be connected are seperated from that.\\ | ||
+ | With JP1 it is possible to select a n external supply (coming from J3),\\ | ||
+ | or the 5V from the RocNet bus.\\ | ||
+ | Indication on board shows the right settings for this jumper.\\ | ||
+ | \\ | ||
+ | :!: **In version 1 it must be absolutely certain that during operation the jumper between pin 2 and 3 may only be connected when capacitor C2 is discharged beforehand.\\ | ||
+ | In version 2 that action is protected. | ||
+ | ** :!: \\ | ||
+ | |||
+ | |||
+ | ===== Total possible led outputs in one RocNet setup ===== | ||
+ | The PCa9622 is configured to be adressed from &H060 to & | ||
+ | Since each chip is controlling 16 Led outputs, the total amount is 256 Led outputs in this RocNet.\\ | ||
+ | \\ | ||
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+ | |||
+ | ===== Adressing the PCA9622 chip. ===== | ||
+ | {{ : | ||
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+ | This board comes , as from factory, with all adresses left open.\\ | ||
+ | The picture shows the four adresses connected to 0V meaning that this chip is addressed to & | ||
+ | Logic ' | ||
+ | ^ Address settings | ||
+ | | Address | ||
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+ | ==== a small correction needed ==== | ||
+ | It appears that version 1 circuits are missing the internal ground connection with the two RJ12 connectors\\ | ||
+ | That can easily be solved with the short wire bridge marked in this picture:\\ | ||
+ | {{: | ||
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