v4.2 designed by Peter JAKAB in 2004-2005
old version in December, 1999

NOTE for beginners: PICs are general purpose microcontrollers which have to be programmed before you can use them in the actual circuit! Check out this link to learn more.

Control up to 8 devices by this easy constructable remote control. It can work as a radio or infrared remote control, depending on the components. Each device output can be configured to be momentary (turned on while you press the button) or latched. Latched outputs can be toggled on/off by one button per channel, or turned on and off by two buttons per channel.

Try it now, before building! Click on the transmitter buttons with the green labels on the left and see how the receiver outputs (K1-K8) change. Change the number of transmitter or receiver channels. Switch the receiver output type between latched and momentary.

Containing a PIC microcontroller, the circuit is very flexible. You can decide which receiver outputs are latched and which are momentary. The Manchester-coded transmitter output is well suited for the cheapest ASK radio modules or for infrared control. The units are configurable to a unique address, which must match to control the devices.

Related project: Learning remote control receiver
Take your existing remote control and control everything with it. This receiver can learn codes from an RC-5 format IR remote control, and associate the buttons to different channels and actions.

Related project: 2^16 remote control encoder and decoder
If you have TTL signals to control remote digital output lines, please check this project instead.

If you have trouble with programming PIC microcontrollers, you can consider builing other circuits based on Holtek HT-12D, HT-12E, Princeton PT2262, PT2272 and Motorola MC145026, MC145027, MC145028 encoders/decoders.

4/8-channel V4.2 radio transmitter

The difference between the 4-channel and the 8-channel version is only the software inside. The 8-channel transmitter has one button (S1-S8) per channel. The 4-channel transmitter uses S1-S4 buttons to turn on, S5-S8 buttons to turn off channel 1-4 (use with latched outputs on the receiver). The D1-D4 diodes and J1-J4 jumpers are optional, and are used to setup the transmitter address. Higher supply voltage results higher transmit power, but V+ range is 2-5.5VDC for the PIC MCU. When V+ is higher than 5VDC, use separate power for the mcu.

Configure & download
What if you can't get a pic16f630?

• use a pic16f676
• try a pic16f628, here is the modified transmitter

  parts list

part	description
C1	100nF ceramic capacitor
R1	10k resistor (1/8W)
D1-D4	1N4148 diode (optional)
S1-S8	tact switch, DTSM 61N or similar
IC1	PIC16F630 or PIC16F676 microcontroller, pre-programmed
TXMOD	radio transmitter module, see text (hardware)
B1	battery between 2-5.5VDC (check TXMOD specs for valid voltage range)

4/8-channel V4.2 infrared transmitter

4/8-channel V4.2 radio receiver

component pinouts

parts list

part	description
C1, C2	22pF ceramic capacitor
C3, C5	100nF ceramic capacitor
C6	10uF 6.3V electrolytic capacitor
CN1-CN8	PCB terminal block, 3-way (DG301)
D1-D8	1N4004 diode
IC1	PIC16F627 or PIC16F628 or PIC16F627A or PIC16F628A microcontroller, pre-programmed
IC2	LP2950CZ5.0 voltage regulator
LED	3mm LED (green)
LED1-LED8	3mm LED (red)
Q1-Q8	BS170 N-channel mosfet transistor
R1-R9	220R resistor (1/8W)
RL1-RL8	G5LE relay, see text for coil voltage selection
S1	piano DIP switch, 4-way
X1	4MHz HC49 crystal
RXMOD	3-pin radio receiver module, see text (hardware)

4/8-channel V4.2 infrared receiver

Acer Aspire: 5749 Bios Link

Acer Aspire 5749 BIOS — Quick Guide and Download Link Info

How to safely attempt the update (If you must):

1. Identify the BIOS Vendor: Press F2 on boot. The Main tab will tell you if you are running Insyde.
2. Battery Check: Ensure your battery is 100% charged AND the AC adapter is plugged in. The Insyde flash utility checks for this and will halt if the battery is low to prevent bricking.
3. The Method: Most Acer updates of this era come as a Windows executable (WinFlash). It is safer to run this from a fresh Windows 7 or Windows 10 install, disabling your antivirus temporarily, as they sometimes interfere with the low-level writing process.

If you need a direct link and the official site is down, let me know, and I can help locate a cached version, but I strongly advise against third-party hosting sites for BIOS files.

For official and safe BIOS updates for your Acer Aspire 5749, you should always use the official Acer support channels. Updating from unofficial sources can risk bricking your device. 🛠 Official Download Link

To find the exact BIOS for your specific build, visit the Acer Support Drivers and Manuals page.

Enter your Serial Number or SNID (found on the sticker on the bottom of the laptop). Alternatively, search by model: Aspire 5749.

Expand the BIOS/Firmware section to see all available versions. The latest version is typically listed as v1.08. ⚠️ Critical Safety Steps Before Updating

Plug in Power: Never update on battery alone; the laptop must be connected to AC power.

Check Current Version: Press Win + R, type msinfo32, and check your "BIOS Version/Date" to see if you even need an update.

Disable BitLocker: If you use Windows Pro, suspend BitLocker protection first to avoid getting locked out.

Don't Touch: Once the update starts, do not close the lid, press the power button, or unplug any devices until it restarts into Windows. 💡 Why Update?

Most updates for this older model focus on hardware compatibility (like upgrading your CPU) or fixing specific boot-up issues. If your laptop is running fine, Acer generally recommends not updating the BIOS. acer aspire 5749 bios link

If you tell me what specific problem you're trying to solve (e.g., black screen on boot, CPU upgrade, or Windows 10/11 compatibility), I can provide more targeted troubleshooting steps. Download Acer Aspire 5749 BIOS 1.08 for OS Independent

Acer Aspire 5749 BIOS Link and Update Guide Finding a reliable Acer Aspire 5749 BIOS link is critical for users looking to resolve system bugs, improve hardware compatibility (such as CPU upgrades ), or ensure system stability. The Acer Aspire 5749 typically uses InsydeH2O BIOS firmware. Acer Aspire 5749 BIOS Download

The safest and most reliable way to obtain the BIOS for your machine is through the Official Acer Support Site. Navigate to the Drivers and Manuals section. Enter your Serial Number , SNID, or search for Aspire 5749 in the model search bar.

Expand the BIOS/Firmware section to find the available versions.

Download Version 1.08: This is widely cited as one of the latest stable versions for this series. Key Specifications & Compatibility Acer Communityhttps://community.acer.com Latest available BIOS version - Acer Community

You're looking for a link to download the BIOS update for the Acer Aspire 5749. Here are some steps to help you find and update the BIOS:

Official Acer Support Website:

1. Visit the official Acer support website: https://www.acer.com/support
2. Click on "Support" and select "Downloads" from the dropdown menu.
3. Enter your device model (Aspire 5749) and click on "Search".
4. Select your device model from the search results.
5. Click on "BIOS" from the list of available drivers.
6. Download the latest BIOS update.

Alternative Method:

1. You can also search for the BIOS update on Acer's global support website: https://global.acer.com/en/support
2. Follow the same steps as above.

Direct BIOS Update Links ( Warning: Not recommended, as links may expire) Acer Aspire 5749 BIOS — Quick Guide and

After searching, I found a few links to BIOS updates for the Acer Aspire 5749:

• Insyde BIOS Update: https://downloadmirror.insyde.com/pub/AS5749-6866/74.6.0.1030/BIOS_Image.rar
• ** Acer FTP Site**: ftp://ftp.acer-euro.com/pub/aspirenb/as5749_aspire_5749_bios_2.09.rar

Please verify the BIOS version and ensure it matches your current version before updating.

How to update the BIOS:

1. Read the user manual or documentation that came with your device for instructions on updating the BIOS.
2. Create a bootable USB drive or use a CD/DVD to update the BIOS.
3. Enter the BIOS settings (usually by pressing F2, F12, or DEL) and follow the on-screen instructions.

Disclaimer: Updating the BIOS can potentially cause issues if not done correctly. Make sure to follow the instructions carefully and ensure your device is connected to a power source during the update process. If you're unsure, consider contacting Acer support or a professional for assistance.

Acer Aspire 5749 is a classic budget laptop that remains a popular choice for hobbyists and value-seekers due to its upgrade potential and solid fundamental design. While its all-plastic chassis and glossy 15.6-inch screen may feel dated, it is a reliable machine for everyday tasks when paired with the right software and firmware. Expert Reviews BIOS & Firmware Overview

Maintaining an up-to-date BIOS on the Aspire 5749 is critical for hardware compatibility, especially if you plan to upgrade the CPU or RAM. Acer Community Latest available BIOS version - Acer Community

To ensure system safety, you should only download BIOS updates from the official Acer Support Drivers and Manuals Acer Community Steps to find the BIOS: Acer Support Aspire 5749 in the model search box or enter your Serial Number/SNID Scroll down to the BIOS/Firmware tab to see all available versions. The most common official version for this model is 2. How to Access the BIOS

If you need to change settings like boot order or system time, use the following hotkeys during the startup process: BIOS Setup Key repeatedly as soon as the Acer logo appears. Boot Menu Key (if enabled in BIOS) to select a temporary boot device. Acer Community 3. Critical Update Precautions

Updating a BIOS (flashing) carries risks. If the process is interrupted, it can "brick" the motherboard. Power Source : Always have your AC adapter connected during the update to prevent power loss. Identify the BIOS Vendor: Press F2 on boot

: Only update if the new version resolves a specific issue you are experiencing or adds support for new hardware. It generally does increase system speed. Format Constraints : The Aspire 5749 uses a Legacy-only BIOS

. It does not support UEFI or GPT boot disks for operating systems like Windows 8.1 or 10 without specific legacy configurations. Acer Community 4. Installation Steps the ZIP file from the Acer Support page

the contents by right-clicking the file and selecting "Extract All". Run the Installer : Right-click the

application file (often found inside a "Windows" folder within the extract) and select Run as Administrator

: The system will automatically flash the BIOS and may restart several times. Do touch the power button during this time. Acer Community specific hardware issues you're trying to solve with this BIOS update? How to update your BIOS on an Acer notebook computer

---

Before You Flash:

• Ensure your laptop is plugged into AC power (battery charged above 20%).
• Close all other programs.
• Do not interrupt power during the update.

Prerequisites:

• The laptop must be plugged in to AC power. A battery failure mid-flash will destroy the laptop.
• Disable your antivirus temporarily (it may falsely block the flash tool).
• Close all applications.

Before You Click "Download" (Crucial Steps)

Updating a BIOS is low-risk but no-fail. Do these three things first:

1. Plug in the AC Adapter: A power outage during a BIOS flash will brick your laptop permanently.
2. Charge the Battery: Ensure the battery is at least 30% charged.
3. Close all programs: You are flashing firmware, not installing a driver.

Troubleshooting: BIOS Recovery

If you downloaded the BIOS link because your laptop is already "bricked" or failing to boot, a standard update may not work. You may need to perform a BIOS Crisis Recovery (often involving a USB flash drive and a specific key combination like Fn + Esc while pressing the power button).

However, if your laptop is currently functioning, simply run the executable file as described above.

Why You Might Need This BIOS

Updating the BIOS on a legacy laptop isn't for fun—it solves specific problems. The v1.10 update for the Aspire 5749 primarily addresses:

• Windows 8/10 Compatibility: Improves UEFI boot behavior for modern OS installations.
• Fan Control: Fixes issues where the fan runs at maximum speed constantly.
• RAM Detection: Ensures the system recognizes 8GB (2x4GB) DDR3 modules correctly.
• CPU Microcode: Allows the laptop to accept newer Sandy Bridge mobile processors (e.g., i5-2540M).

hardware

FAQ

references