User Interface - Lcd Driver Based On The HT1621 Controller

Application Note Abstract This Application Note describes implementation of a liquid crystal Display (LCD) driver based on the widely available HOLTEK HT1621 LCD Controller Methods and algorithms of Display control are described and an API library is provided. The LCD used in this example was a customer’s custom part. The proposed algorithms CAN be easily adapted to any custom LCD panel connected to the controller. Introduction LCDs are widely used as data Display devices in embedded systems. Among the features that have made LCDs popular are low price, low power dissipation, lightweight, durability, reliability, and broad support by dedicated ICs for Communication with Microcontrollers A good example of an LCD Driver is the Hitachi character LCD Driver HD44780, the industry standard. This dot-matrix LCD Controller is supported by PSoC APIs. It is useful in applications that permit alphanumeric data Display However, specialized Displays are often needed. Specialized Displays keep end- product prices low, simplify the Interface between the Microcontroller and LCD Driver and decrease weight and size parameters. Examples of specialized Displays include Clocks calculators, telephones, and home and industrial appliances. This implementation is based on one of these dedicated drivers, the HT1621. This Application Note addresses the proposed implementation in two parts: ƒ General Description ƒ LCD Driver Implementation General Description The HT1621 driver is a 128-segment (32x4), multi-functional LCD Driver with memory mapping. The software configuration feature of HT1621 makes it suitable for many LCD applications, including LCD modules and Display subsystems. Only three or four connections are required for interfacing between the host controller and the HT1621. A structural schematic of the Display system is shown in Figure 1. This structure requires few external components and uses only three Interface connections. The system consists of the PSoC, HT1621 controller, and an LCD panel. The HT1621 besides its primary function as an LCD controller, has peripherals including the watchdog Timer time base generator and the Tone frequency generator. For more information about these features, refer to the HT1621 data sheet. Note that the controller has an on-chip RC Oscillator (256 kHz) for controlling the LCD and peripherals. This General Description focuses on the components and functions of the HT1621 driver that relate directly to the LCD: ƒ Display Memory RAM ƒ LCD Driver in HT1621 ƒ Command Format ƒ Interfacing with HT1621

Big Motor Driver TLP250

I have posted a motor controller design that is supposed to be simple, robust, cost effective, and able to handle high currents.  Above is a schematic of the first part of the design.  I will post an updated version to include a PIC to accept commands from a PC, Microcontroller, etc. and provide the direction/PWM signals to the H-bridge.  I am still working on the PCB but here is what I have done so far for review/critism.  What is not shown in the schematic are the in-line fuses for protection.

For the PIC, I use MBasic and PicBasic Pro to write the code.  This should convert easly to the BS2 and PicAxe.


 I updated the schematic again.  As suggested I changed the MOSFET driver to a TLP250 and dropped the 1K resistor across the Gate to source.
Update the schematic to show that the logic grounds are isolated from the dirty motor grounds.

Finished the PCB design.  Once boards are complete will test and post schematic and board files once any kinks are worked out.

I got the prototype boards back from the manufacture two days after I sent them off.  As you'll see below, the quality is excellent.  Tonight I populated the board and checked out functionality with a multimeter prior to testing with a motor.  I managed to get everything put together right so on to the smoke check.  I hooked up a good size motor with a lot of torque and applied power.  The motor moved in both directions and the MOSFET did not even get warm.  This test was applying full power to the motor and not PWM.  Next, I'll write some code and test functionality with PWM hooked to my Oscope so I can check the signals and see how high I can take the frequency.  I'll get around to posting some video but, in the mean time, here are some pictures of one of the finished boards.

Water towers water level controller circuit PC817

IC2 can use a variety of 555 time base integrated circuits. IC3 is the infrared receiver decoder CX20106A. IC4 can use 4N25, 4N26, PC817 and other optocoupler. Part of the infrared receiver can purchase finished infrared receiver components or integrated infrared receiver,it’s easy to produce and improve reliability. VD1, VD2 and VD3 ​​can use infrared transmitter and receiver diodes of TVremote control. J chooses to use ​​a new selection of memory self-locking relay,the shape of this relay is same as the general replay, the difference is that the pullis not required to maintain current,justwhen pulling and releasingit requires a certain pulse drive power, then the mechanical structure maintains locked state.

motor controller for R/C models LL4148

The complete circuit diagram of the motor control is shown in Figure 1. The schematic includes all components for unidirectional as well as bidirectional use. The desired version is chosen before building the circuit. Your choice therefore determines the components used. The circuit has been kept as compact as possible. The result: a motor control weighing less than 25grammes.

Resistors:
R1 = 4kOhm, SMD
R2 = 100Ohm, SMD
R3 = 470Ohm, SMD
R4,R6 = 100kOhm, SMD
R5 = 10Ohm SMD
R7 = NTC, 100kOhm
R8 = 1kOhm, SMD
R9 = 10kOhm, SMD

Capacitors:
C1,C2 = 15pF, SMD
C3,C5 = 100nF, SMD
C4 = 10nF, SMD
C6 = 47µF 10V SMD

Semiconductors:
D1 = LL4148*
D2 = MBR2045CT*
T1 = BC517
T2,T3,T4 = BUZ11
T5 = IRF9530
IC1 = PIC16C84 (order code 966510-1)
IC2 = L4940V5
IC3 = PC827

Miscellaneous:
K1 = 10-way pinheader
X1 = 4MHz quartz crystal
Printed circuit board and programmed PIC (IC1): set order code 960095-C
PIC also available separately: order code 966510-1

12V Low side and High side PWM Motor/Light Controller IRFZ48N

 

 

Here these two schematics are variations on addition PWM circuit that I designed. The diagrams are for 12V operation alone and there are aerial ancillary (common ground) and low ancillary (common +12V) versions. The low ancillary adaptation of the ambit uses an N Channel FET, the aerial ancillary adaptation of the circuit uses a P Channel FET. N Channel accessories tend to handle added accepted than P Channel devices, they are additionally beneath expensive. The aerial ancillary adaptation of the ambit is advantageous back one ancillary of the bulk has to be grounded.

This Circuit can about-face a adequately aerial bulk of current, an IRFZ34N MOSFET can handle over 35 Amps if affiliated to a able calefaction sink. Higher ability FETs, such as the IRFZ48N or IRF1010Z can be commissioned if alike beyond currents are required. It is additionally accessible to affix assorted FETs in alongside for alike added accepted capacity. Always use thermally conductive grease amid the FET and the calefaction sink, and bethink that the calefaction bore is electrically live.

Inductive endless (motors) may crave appropriate affliction back they can accomplish ample voltage spikes that can accident the MOSFET. Replacing the 1N4002 with a fast accretion diode may advice blot the about-face voltage bang back active an anterior bulk such as a motor. If you use these circuits for abstracts with electric vehicles, be abiding to install a ambit breaker in alternation with the battery, the ambit breaker should be accessible to ability by the driver. This is abnormally important due to the actuality that back MOSFETs fail, they generally abbreviate out, abrogation the motor on at abounding speed.

Note that the pwm ascendancy has an adverse aftereffect on these two circuits, the low ancillary adaptation is on with a aerial pin 7 achievement voltage and the aerial ancillary adaptation is on with a low output.

The inductor on the aboideau ancillary of the ability MOSFET transistor can be a ferrite bean or a few turns of wire captivated about a 10 ohm, 1/4W resistor. The purpose of this allotment is to anticipate RF oscillations from occurring in the MOSFET circuitry.