KFLOP Hardware Info - Revision history

TK: /* KFLOP Inputs Floating High */

2018-01-11T00:05:57Z

‎KFLOP Inputs Floating High

BradG at 16:32, 19 October 2015

2015-10-19T16:32:04Z

TK: KFLOP Input Filters

2015-10-14T23:46:43Z

KFLOP Input Filters

TK at 16:32, 12 October 2015

2015-10-12T16:32:23Z

TK: Created page with "KFLOP - DSP-based microcontroller with 1.2 GFLOPs of processing power, a 100k Gate FPGA, 16 Mb SDRAM, 8 axes of control, lots of I/O and the ability to program in C File:KF..."

2015-10-12T16:24:03Z

Created page with "KFLOP - DSP-based microcontroller with 1.2 GFLOPs of processing power, a 100k Gate FPGA, 16 Mb SDRAM, 8 axes of control, lots of I/O and the ability to program in C File:KF..."

New page

KFLOP - DSP-based microcontroller with 1.2 GFLOPs of processing power, a 100k Gate FPGA, 16 Mb SDRAM, 8 axes of control, lots of I/O and the ability to program in C

[[File:KFLOP_perspective1_400.jpg|none|link=|394x241px]]

{| id="table8" border="1" width="524" cellspacing="1"
|-
||[http://dynomotion.com/Help/SummaryKFLOP.htm Summary]
| width="260"|
[http://dynomotion.com/Help/KFLOPQuickStart/KFLOPQuickStart.htm Quick Start/U][http://dynomotion.com/Help/KFLOPQuickStart/KFLOPQuickStart.htm SB Driver Installation]

|-
||[http://dynomotion.com/Help/SpecificationKFLOP.htm HW/SW Specification]
| width="260"|
 [http://dynomotion.com/Help/SchematicsKFLOP/LayoutKFLOP.htm Board Layout]

|-
||[http://dynomotion.com/Help/BlockDiagramKFLOP.htm Block Diagram]
| width="260"|
[http://dynomotion.com/Help/SchematicsKFLOP/ConnectorsKFLOP.htm Hardware/Connector Description ]

|-
||[http://dynomotion.com/Help/AnalogIOScreenKFLOP/AnalogIOScreen.htm Analog IO Screen]
| width="260"|[http://dynomotion.com/Help/DigitalIOScreenKFLOP/DigitalIOScreen.htm Digital IO Screen]
|-
|| [http://dynomotion.com/Help/SchematicsKFLOP/KFLOPFunctionalDiagram.htm Functional Diagram]
| width="260"|[http://dynomotion.com/Help/VirtualComPortwithKFLOP.pdf Virtual COM Port Driver Installation]
|}

← Older revision		Revision as of 00:05, 11 January 2018
Line 29:		Line 29:
	==Hardware Topics==		==Hardware Topics==
	[[Noise - Typical Problems and Resolutions\|Dealing with noise using KFLOP input filters]]		[[Noise - Typical Problems and Resolutions\|Dealing with noise using KFLOP input filters]]
		+
		+
		+
		+	==KFLOP Inputs Floating High==
		+	A common question is: '''''"I don't have a KFLOP Input Connected to anything. Why is it reading high?"'''''
		+
		+	If a KFLOP input is not connected then it may float to any voltage. KFLOP inputs (those without pull down resistors) are very high impedance (many megohms). The slightest leakage current due to moisture, parasitic inductance, capacitance, etc can make the voltage non zero. Often a ribbon cable will cause one floating input to follow an adjacent signal in the cable that is being driven.
		+
		+
		+	KFLOP inputs are voltage sensitive and require almost zero current. Unlike something like a light bulb that requires significant current and will go to 0V and off if disconnected. KFLOP Inputs must be driven high (>2.0V) and low (< 0.4V). If not driven they may be high or low.
		+
		+
		+	A simple switch can not normally be used to drive a KFLOP input because when the switch is open it will float to any state. An exception to this is the 16 KFLOP inputs on JP4 and JP5 that have 150ohm pull down resistors. Those will be guaranteed to be low if disconnected. So a simple switch to 3.3V might be used to drive those.
		+
		+
		+	KFLOP inputs are all 3.3V LVTTL and have protection diodes connected to the 3.3V power supply (and GND) to prevent the input from floating too high (from leakage or static electricity) and burning out. For this reason KFLOP inputs should never be driven higher than 3.8V. Because of the internal construction of the FPGA (where differential pairs share some common circuitry) if an input is driven high enough to be forced to clamp, some clamping current may leak into the complimentary signal pair input. This should be avoided.

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 |}
-==KFLOP Input Filters==
+==Hardware Topics==
-KFLOP inputs are very fast and therefore susceptible to narrow noise glitches.  KFLOP doesn't have selectable digital filtering.  It is usually best to fix the source of the problem in hardware.  Otherwise you might reduce the frequency of the problem but not eliminate it entirely.  You might add a Filter Capacitor (such as a 0.1uf ceramic capacitor) from the KFLOP input pin to the KFLOP GND (in very close proximity to KFLOP).  <br /><br />To filter the inputs in software you can do so with a User Program that samples the input, performs some filtering algorithm, and sets/clears a KFLOP Virtual I/O Bit (ie bits 48-63) based on the result.   Then configure the KFLOP Axis to monitor the Virtual Inputs rather than the real inputs.   The ExternalButtons.c example shows how multiple inputs can be monitored and debounced using a single non-blocking loop using a state driven approach.  See the Debounce() function, how its used, and the 3 global variables needed for every input to keep track of the states of the input.
+[[Noise - Typical Problems and Resolutions|Dealing with noise using KFLOP input filters]]

← Older revision		Revision as of 23:46, 14 October 2015
Line 26:		Line 26:
	\| width="260"\|<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/VirtualComPortwithKFLOP.pdf Virtual COM Port Driver Installation]</span>		\| width="260"\|<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/VirtualComPortwithKFLOP.pdf Virtual COM Port Driver Installation]</span>
	\|}		\|}
		+
		+	==KFLOP Input Filters==
		+	KFLOP inputs are very fast and therefore susceptible to narrow noise glitches. KFLOP doesn't have selectable digital filtering. It is usually best to fix the source of the problem in hardware. Otherwise you might reduce the frequency of the problem but not eliminate it entirely. You might add a Filter Capacitor (such as a 0.1uf ceramic capacitor) from the KFLOP input pin to the KFLOP GND (in very close proximity to KFLOP). <br /><br />To filter the inputs in software you can do so with a User Program that samples the input, performs some filtering algorithm, and sets/clears a KFLOP Virtual I/O Bit (ie bits 48-63) based on the result. Then configure the KFLOP Axis to monitor the Virtual Inputs rather than the real inputs. The ExternalButtons.c example shows how multiple inputs can be monitored and debounced using a single non-blocking loop using a state driven approach. See the Debounce() function, how its used, and the 3 global variables needed for every input to keep track of the states of the input.

@@ Line 3: / Line 3: @@
 [[File:KFLOP_perspective1_400.jpg|none|link=|394x241px]]
-{| id="table8" border="1" width="524" cellspacing="1"
+{| id="table8" style="height: 164px;" border="1" width="700" cellspacing="1"
 |-
-||<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/SummaryKFLOP.htm Summary]</span>
+| style="width: 350px;"|<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/SummaryKFLOP.htm Summary]</span>
-| width="260"|
+| style="width: 350px;" width="260"|
-[http://dynomotion.com/Help/KFLOPQuickStart/KFLOPQuickStart.htm  <span style="font-family: Arial Black; font-size: small;">Quick Start/U</span>]<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/KFLOPQuickStart/KFLOPQuickStart.htm SB Driver Installation]</span>
+[http://dynomotion.com/Help/KFLOPQuickStart/KFLOPQuickStart.htm  <span style="font-family: Arial Black; font-size: small;">Quick Start/USB Driver Installation</span>]
 |-
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 ||<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/BlockDiagramKFLOP.htm Block Diagram]</span>
 | width="260"|
-[http://dynomotion.com/Help/SchematicsKFLOP/ConnectorsKFLOP.htm  <span style="font-family: Arial Black; font-size: small;">Hardware/Connector Description</span> ]
+[http://dynomotion.com/Help/SchematicsKFLOP/ConnectorsKFLOP.htm  <span style="font-family: Arial Black; font-size: small;">Hardware/Connector Description</span>]
-|-
+|- style="height: 30px;"
 ||<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/AnalogIOScreenKFLOP/AnalogIOScreen.htm Analog IO Screen]</span>
 | width="260"|<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/DigitalIOScreenKFLOP/DigitalIOScreen.htm Digital IO Screen]</span>
-|-
+|- style="height: 30px;"
 ||<span style="font-family: Arial Black; font-size: small;"> [http://dynomotion.com/Help/SchematicsKFLOP/KFLOPFunctionalDiagram.htm Functional Diagram]</span>
 | width="260"|<span style="font-family: Arial Black; font-size: small;">[http://dynomotion.com/Help/VirtualComPortwithKFLOP.pdf  Virtual COM Port Driver Installation]</span>
 |}